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Intellectual Disability & Global Developmental Delay

Overview

Intellectual disability (ID) describes a heterogeneous group of conditions characterized by low or very low intelligence and deficits in adaptive behaviors, without reference to etiology. [Sattler: 1988] The diagnosis is clinical and does not rely on genetic testing. Intellectual disability is divided into mild, moderate, severe, and profound categories. IQ has historically been used to determine the severity of intellectual disability and is often still used for determining eligibility for disability and state resources. However, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) [American: 2013] and other organizations are encouraging more emphasis on function in determining the degree of disability.
Patients with mild intellectual disability may function well with some support or supervision, while those with profound intellectual disability require assistance in every aspect of life. While there is no treatment for ID, some of the conditions causing it (e.g., metabolic errors or hypothyroidism) can be treated. Much also can be done to limit secondary disabilities, optimize functional abilities, and assist the affected child and his/her family in adapting to the condition. In children younger than 5 or with profound delay who cannot be reliably tested, the term “intellectual disability and global developmental delay” is often used. However, with an increased emphasis on function in diagnosis, it would be reasonable to diagnose children with clear, non-reversible global delay as having intellectual disability.

Other Names & Coding

Developmental delay Global developmental delay Static encephalopathy (generic term for brain pathology affecting any function)
ICD-10 coding

F70, Intellectual disability, mild

F71, Intellectual disability, moderate

F72, Intellectual disability, severe

F73, Intellectual disability, profound

G93.40, Static encephalopathy (encephalopathy, unspecified)

F88, Global developmental delay (other disorders of psychological development)

R62.50, Developmental delay (unspecified lack of expected normal physiological development in childhood)

Coding for Intellectual Disability (icd10data.com) provides further coding details.
Note that static encephalopathy (G93.40) or global developmental delay (F88) are considered ICD-10 diagnostic codes, while developmental delay is a finding/symptom code. Diagnostic codes are preferred for billing purposes.

Prevalence

The prevalence of ID in the general population is approximately 0.8:100; prevalence for severe ID is approximately 6:1,000. [Zablotsky: 2019] [Zablotsky: 2017] [American: 2013]

Genetics

All children with ID without a known etiology should have a genetic evaluation; not all should have genetic testing. Obtaining an etiologic diagnosis by genetic testing is possible in less than ½ of patients with intellectual disability. [Fan: 2018] The yield is higher in patients with ID and additional syndromic features. [Battaglia: 2013]

Prognosis

Measures of intellect and adaptive behavior are somewhat predictive of the eventual ability to live independently. For instance, individuals with mild to moderate ID should become relatively self-sufficient with appropriate family and community support. Individuals with severe and profound ID will need a great deal of support and do not usually live independently. They also tend to have shortened life expectancies, often due to the conditions causing ID.

Practice Guidelines

Practice Guidelines are limited by the level of evidence and low diagnostic yields for much of the recommended testing, as well as limited insurance coverage of some tests. These guidelines should be used with these caveats in mind. A combination of the 2 guidelines below is usually the most cost-effective and yields the best results.

Moeschler JB, Shevell M.
Comprehensive evaluation of the child with intellectual disability or global developmental delays.
Pediatrics. 2014;134(3):e903-18 (reaffirmed 2020). PubMed abstract / Full Text

Shevell M, Ashwal S, Donley D, Flint J, Gingold M, Hirtz D, Majnemer A, Noetzel M, Sheth RD.
Practice parameter: evaluation of the child with global developmental delay: report of the Quality Standards Subcommittee of the American Academy of Neurology and The Practice Committee of the Child Neurology Society.
Neurology. 2003;60(3):367-80. PubMed abstract / Full Text

Roles of the Medical Home

A diagnosis of ID is important to allow the family to begin making realistic plans for the child's education and future. The diagnosis also allows the child to qualify for Early Intervention, special educational services, and, depending on the family's financial status, entitlement programs, such as disability services.
The medical home can:
  • Schedule health maintenance visits frequently enough to identify and address new issues.
  • Ensure that the family has access to reliable information, community services, and resources.
  • Coordinate care and interpret information or advice from specialists.
  • Facilitate access to private providers or other systems of care if the child does not qualify for government- or school-sponsored services, such as occupational, physical, or speech therapies.
  • Assess parental stress, sibling problems, and social supports during follow-up visits; referral to support organizations and agencies may be particularly useful if the family is headed toward a crisis.
  • Connect families with others in similar situations in order to provide support and alleviate the sense of isolation.
  • Ensure that children with ID are provided opportunities for socializing and recreation.

Clinical Assessment

Overview

Important steps in the clinical assessment of a child with ID include:
  1. Treatable diagnoses that might mimic ID, such as severe auditory or visual impairment or neurologic disorders, must be ruled out.
  2. Reversible or treatable causes, such as hypothyroidism, toxic exposures, or other metabolic conditions, should be considered and tested.
  3. Suspicion of ID should be confirmed with norm-referenced testing for IQ and adaptive functioning. Opinion in the literature is mixed regarding the earliest age at which a diagnosis of ID is reasonable. It is usually possible in the preschool years, earlier for more severe cases, but not reliably until age 5. [Shevell: 2003] Diagnosis of ID and determination of the etiology are separate processes. While the etiology may be elusive, a diagnosis of ID should be possible in nearly all affected children. The Portal's issue page on Missing issue with id: 15179e9f.xml lists available tests for IQ/development, adaptive behavior, achievement, and behavior. Most children will be evaluated by psychologists in the community or particularly in schools. Mental Health Evaluation/Assessment (see NM providers [8]) and General Counseling Services (see NM providers [10]).
  4. Determining the severity of ID with psychometric and adaptive function testing can help determine prognosis for independent living.
  5. Determine the needs for educational interventions and support for the child and family through testing and comprehensive evaluation by the school and/or community agencies and professionals.
  6. Identify the genetic or environmental non-reversible etiology, if possible, through medical history (including 3 generation family history) and physical exam (e.g., a large head circumference may indicate fragile X syndrome, or distinctive facial features might suggest Cornelia de Lange syndrome). An etiology can be found in about 2/3 of individuals with severe ID but in only about 1/3 of those with mild ID. A small number of etiologies may be treatable. [Engbers: 2008] [Mueller: 2008] Knowing the cause can help determine prognosis, the risk of recurrence in the family, and predict the child's ability to live independently in the future. The process of finding this etiology should be happening concurrently with the formal testing and procurement of needed resources.

Pearls & Alerts for Assessment

Developmental delay vs. intellectual disability

The term “global developmental delay” (GDD) is usually reserved for younger children (typically younger than 5 years), and the term “intellectual disability” (ID) is usually applied to older children when IQ testing is valid and reliable. ID involves both cognitive and adaptive or functional components. Delays in development, especially those that are mild, may be transient and lack predictive reliability for ID or other developmental disabilities. Developmental delay affecting multiple development domains may be intellectual disability, but further testing or passage of time may be needed to clarify this. Patients with severe delays in multiple domains have a higher likelihood of having ID and, if profound, may be diagnosed with ID sooner.

Children with autism may have normal intelligence

It may be more difficult to evaluate the cognition of children with an autism spectrum disorder.

Misdiagnosis of seizures

Many children with ID display behavior or have physiological events that appear clinically similar to seizures, but they cannot be distinguished based on observation alone. These patients should be referred to a neurologist for further evaluation. [Chapman: 2011]

Screening

For the Condition

Developmental Screening, an important component of routine well-child care, should identify many children with developmental delay early in life.

Presentations

Presentation typically includes cognitive skills delay, language delay, and adaptive skills delay. Developmental delays vary depending on the etiology and degree of ID.

Clinical Classification

The severity of ID is classified by degrees of intellectual and adaptive functioning. This is less focused on IQ now and more on function, making the differentiation between degrees of functioning less concrete.
  • Borderline: IQ low and functional status is low, but not below the 3rd percentile. These patients often require resources, but they may not meet criteria (usually set by each state) for intellectual disability
  • Mild: Able to function with some support, the majority of patients with ID fall into this category
  • Moderate: More limited independent function, more assistance required
  • Severe: Very minimal adaptive function with assistance
  • Profound: No adaptive functioning possible, even with assistance, extremely low IQ

Differential Diagnosis

Autism spectrum disorder, specific language problems, and hearing problems may be confused with ID in young children or coexist with ID. ID can also be confused with developmental delay, which may be less extensive or improve overtime to more closely reach age-based normal function. Static encephalopathy is a broad term for any non-progressive neurological pathology and does not apply to only ID. Autism Spectrum Disorder and Hearing Loss and Deafness provide screening and diagnosis information for these conditions.
ID should only be diagnosed when there is clear evidence that cognitive abilities and adaptive behaviors are significantly below average (usually less than or equal to the 3rd percentile), and there is no reasonable expectation that this will change significantly with time. Temporary conditions (e.g., the convalescent period after a brain insult such as meningitis or trauma, the response to early neglect, or the response of children soon after foreign adoption) are excluded by definition. ID also excludes the very young when cognitive ability and adaptive behaviors are not easily measurable. This is especially true in mild cases because children with mild developmental delay are more likely to improve and not meet the defining characteristics noted above.

Medical Conditions Causing Intellectual Disability & Global Developmental Delay

Out of the hundreds of known causes of ID, 1/2 are thought to be exogenous (e.g., prenatal exposure to infection or toxins such as alcohol); the other 1/2 are likely genetic. Currently, up to 1/2 of the genetic causes of intellectual disability/developmental delay may be identified with whole-exome sequencing. [Stojanovic: 2020] When seeking the cause for a particular child, it is often useful to consider broad categories of etiologies, including:
  • Inherited/chromosomal: PKU, hypothyroidism, fragile X syndrome, Trisomy 21, tuberous sclerosis, autism. Approximately 15% of males with nonspecific ID may have an X-linked syndrome. [Stevenson: 2009]
  • Factors associated with pregnancy: Intrauterine infections, toxins (including drug and alcohol abuse, prescription drug effects), abnormal brain development (e.g., cortical dysplasia), and hypoxia/ischemia (placental insufficiency)
  • Birth-related hypoxic-ischemic encephalopathy, extreme prematurity (associated with delays, but not independently causal of ID)
  • Post-natal infection, head injury, abuse/neglect, malnutrition, lead/mercury exposure

Comorbid & Secondary Conditions

Patients with ID have a higher rate of comorbid neurological and psychiatric conditions. Some of these may manifest differently due to the ID. [Oeseburg: 2011]

History & Examination

Since knowledge about genetic etiologies is increasing so rapidly, patients with ID, but without an etiology, should be re-evaluated periodically. Evaluation of development, behavior, intellect, vision, hearing, and adaptive functioning will guide ongoing interventions and anticipate evolving problems. If abilities seem to be deteriorating, further investigations are necessary, and referrals to pediatric neurology and genetics are recommended. Careful history is needed to elicit and clarify parental concerns of regression.

Current & Past Medical History

Ask about decreased growth or overgrowth, infection, head injury, abuse/neglect, malnutrition, unusual eye movements, concern for seizures, motor abnormalities including asymmetry, social skills, lead/mercury exposure, hearing and vision problems, and previous testing.
Parents may not realize that sleep issues are potentially treatable; the medical home should ask about the child’s sleep habits, history of snoring, and any daytime sleepiness at well-child visits. See Screening for Sleep Problems and Sleep Issues.

Family History

A family medical history (3 generations, if possible) may provide clues to etiology and prognosis. Family history should include ethnic background, metabolic diseases, parental consanguinity, relatives with autistic features, multiple miscarriages, or unexplained infant/childhood deaths. Attention should be paid to the sex of affected relatives because there are several X-linked ID syndromes.

Pregnancy/Perinatal History

Ask about:
  • Difficulty conceiving, intrauterine infections or maternal illness, toxins (including drug and alcohol abuse, prescription drug effects), abnormal brain development (e.g., cortical dysplasia), and hypoxia/ischemia (placental insufficiency)
  • Birth-related factors such as hypoxic-ischemic encephalopathy during labor (and Apgar scores) and extreme prematurity
  • Birth weight/height and occipital frontal circumference (OFC) for evidence of placental insufficiency or a genetic syndrome
  • Prenatal screening or testing, type of delivery and why, weight gain and difficulty feeding during the first few weeks, and bonding/attachment

Developmental & Educational Progress

Ask about the time of achievement of developmental milestones. Be specific regarding timing whenever possible. Children with more severe ID are likely to have all developmental milestones delayed from an early age, whereas children with mild ID are more likely to display normal early milestones, especially in the gross motor domain. In addition to asking the child and family directly, reports from Early Intervention or school, including evaluations and report cards, help monitor progress in this area.
Ask about behavior problems and Self-injurious Behavior; mental health problems are frequent in children and adolescents with ID.

Maturationalprogress

Ask about signs of puberty when appropriate, and the ability of the child and family to handle the changes.

Social & Family Functioning

Ask about family functioning, parental jobs, financial resources for caring for a child with ID, and family support systems.

Physical Exam

General

Observe behavior and interaction, including quality of eye contact, attention/focus, interaction, repetitive movements, hand flapping, or aggression.

Growth Parameters

Ht | Wt | OFC for deviations from typical growth charts, head shape, presence of open fontanelle or early closure, failure to thrive, and whether symmetric or head-sparing, any evidence of asymmetric growth (right versus left)

Skin

Look for abnormal textures, hyper- or hypopigmentation (use Wood’s lamp if possible), freckling pattern, eczema, and hemangiomata.

HEENT/Oral

Note head size and shape. Look for distinctive facial features. Ask parents who the child looks most like in the family. Look for epicanthal folds, ear position/shape/size, prominence of chin or forehead, size and shape of eyes, ears, mouth, philtrum. Check hair for abnormal texture or color.

Abdomen

Hepatosplenomegaly

Genitalia

Size, structure

Extremities/Musculoskeletal

Look for single palmar creases, clinodactyly, increased spacing between digits, overlapping digits, size of hands/feet, nail abnormalities, presence of contractures, scoliosis, asymmetry of the length of limbs, and hyperextensibility.

Neurologic Exam

Check for spasticity, tone, balance, coordination, dystonia, ataxia, and chorea.

Testing

Sensory Testing

Hearing and vision testing are important for identifying any impairments, which are a common cause or contributor to ID. Periodic retesting is indicated, particularly if deterioration in function is noted.

Laboratory Testing

Metabolic disorders are identified as the cause of ID in 1-5% of cases of ID. Although newborn screening identifies many of these disorders, further metabolic testing may be necessary. [Engbers: 2008] Other signs/symptoms that might prompt targeted testing include: stigmata of hypothyroidism, seizures, lethargy, vomiting, abnormal urinary odors, and failure to thrive. Deterioration of a child's developmental status should prompt further testing as it may be suggestive of a degenerative disease. [Moeschler: 2014]

Imaging

A brain MRI will identify an abnormality in about 40% of patients with specific findings, such as microcephaly or a focal neurologic abnormality; in the absence of clinical clues, the yield is only about 14%. An MRI may still be cost-effective as a once-in-a-lifetime test when an etiology cannot be identified, particularly when results might be important in family planning and genetic counseling. The American Academy of Neurology and Child Neurology Society recommend neuro-imaging as part of evaluating the child with ID [Shevell: 2003], whereas the American College of Medical Genetics recommends that neuroimaging not be considered "standard of care" in the absence of specific neurologic findings. [Curry: 1997] Others suggest MRI and magnetic resonance spectroscopy be performed in children with unexplained ID. [Battaglia: 2003]
MRI is preferred over CT in almost all cases (unless the examiner is looking for calcifications, as in congenital CMV). The risk of sedation for an MRI and the parents' desires should be considered, along with the potential utility of the information gained.
An EEG only should be performed when clinical seizures are present. When a seizure syndrome is suspected, an abnormal EEG does not add to the evaluation or treatment unless there are concerns for seizures.
A skeletal survey and other imaging may be recommended as part of a genetics consultation. A sleep study should be performed if clinically indicated.

Genetic Testing

Chromosomal microarray (CMA) is now considered a first-tier diagnostic test in all children with global developmental delay and/or ID, replacing karyotyping and FISH. This type of high-resolution analysis for small chromosomal deletions and duplications results in a diagnostic rate of about 12%, at least twice the standard karyotype rate. [Moeschler: 2008] High-resolution karyotyping should be used as a first test only when there is an obvious chromosomal syndrome (e.g., trisomy 21) or a family history of chromosomal rearrangements.
If no etiology is found on CMA, testing for fragile X syndrome may be warranted even when the child does not fit the clinical syndrome, particularly if history or exam findings are suggestive of a genetic cause. [Curry: 1997] Genetic testing is best guided by a geneticist or neurologist.
Both whole exome and whole genome testing are rapidly becoming more readily available and affordable as testing options. These tests should only be performed after the family is referred to either a geneticist or genetic counselor to discuss implications.
Medical home providers should work closely and communicate clearly with the consulting geneticist or genetic counselor when interpreting CMA test results. [Moeschler: 2014] Findings may be pathogenic, benign, or a variant of unknown significance. Variants of unknown significance are often the most challenging to explain to families.

Other Testing

A positive developmental screen should lead to a confirmatory evaluation and, if significant developmental delay is found, full Psychometric Testing is performed. Testing strategies will depend on age and degree of developmental delay.
Norm-referenced testing for IQ and adaptive functioning is critical to confirm the diagnosis, provide some idea of the child's prognosis, guide therapeutic interventions, and, in some cases, a diagnostic workup.

Specialty Collaborations & Other Services

General Counseling Services (see NM providers [10])

Once the diagnosis of developmental delay/ID is suspected, the medical home clinician should have the child tested by psychology (via the educational or medical systems), and then decide whether to refer to neurology, genetics, or another subspecialist based on the history and physical exam.

Medical Genetics (see NM providers [2])

When a diagnosis of ID is confirmed, a genetic evaluation is recommended. A child without a confirmed etiology should periodically be re-evaluated by genetics since knowledge of new genetic syndromes, and new genetic testing is evolving rapidly. Genetic counseling may also be appropriate for the family.

Biochemical Genetics (Metabolics) (see NM providers [1])

If a metabolic etiology is suspected, the child with ID should be evaluated by a metabolic geneticist. Additional metabolic laboratory studies/screening may be indicated.

Pediatric Neurology (see NM providers [5])

Children with specific neurologic problems, such as seizures, abnormal tone, motor asymmetry, or developmental regression, should be seen by neurology and followed as needed for ongoing management.

Pediatric Physical Medicine & Rehabilitation (see NM providers [3])

Physiatrists may be helpful in directing services such as physical therapy, occupational therapy, and feeding management. They can also evaluate needed adaptive equipment and recommend helpful programs available through the school system.

Pediatric Ophthalmology (see NM providers [6])

In addition to finding and treating visual impairment, a pediatric ophthalmologist may find etiologic clues (e.g., cherry red spot, papilledema, or optic nerve pallor) from ophthalmologic exams.

Developmental - Behavioral Pediatrics (see NM providers [2])

Developmental pediatricians can offer a complete developmental evaluation and assist in coordinating services. They may also periodically evaluate a child's developmental progress, guide parental expectations, and establish an ongoing plan for ever-changing educational needs.

General Counseling Services (see NM providers [10])

Comprehensive assessment of the domains of intellectual, social, cognitive, behavioral, academic, and emotional functioning helps identify strengths and weaknesses, formulate a diagnosis, and implement recommendations for interventions. Periodic visits may be helpful in identifying associated problems such as ADHD or mood disorders, which, if not treated, may hinder educational progress and lead to additional psychosocial barriers.

Psychiatry/Medication Management (see NM providers [3])

Consider referral if mental health problems, such as depression or anxiety, are suspected; if there is a strong family history of psychiatric illness; or for difficult behavior problems. Refer for medication management for these complex psychiatric and behavioral issues as needed.

Sleep Study/Polysomnography (see NM providers [2])

A sleep study may be indicated in the setting of snoring, apnea spells, frequent nighttime awakenings, parasomnias, or excessive daytime sleepiness. While adults manifest fatigue by appearing tired, children can appear hyperactive or distracted.

Treatment & Management

Pearls & Alerts for Treatment & Management

Underlying condition can cause challenging behaviors

Carefully check for underlying medical conditions, such as dental abscess, constipation, or other causes of pain, which may be causing challenging behaviors in individuals who may not be able to express their needs.

Perceived regression as child ages

The degree of ID is generally stable throughout life, although it may seem to be worsening as the child gets older and gaps in ability widen when compared with peers. Even children with profound ID may differ little from their peers at 1 year of age but are very different at age 10. Concern for regression, as opposed to stable disability, would be a reason to consider referral to a neurologist or developmental pediatrician. An in-depth discussion with parents can usually clarify whether the child is having perceived or actual regression.

How should common problems be managed differently in children with Intellectual Disability & Global Developmental Delay?

Growth or Weight Gain

Some causes of ID may also limit physical activity or self-regulation; risk of obesity is higher and should be actively monitored. See Obesity in Children &Teens.

Development (Cognitive, Motor, Language, Social-Emotional)

Impaired communication skills often manifest as aggressive or disruptive behavior. Consider communication aids and interventions for children with these types of social-emotional issues.

Over the Counter Medications

Patients with ID may have less ability to compensate for the sedating effects of medication and may react differently to over-the-counter medications than their peers. In addition, patients with ID are often taking medications to manage their symptoms. Providers should be mindful of any OTC medications or supplements the family is using.

Prescription Medications

Start new medications at low dosing with gradual titrations and watch for polypharmacy complications. Medications that do not seem to help within an appropriate window should be removed.

Systems

Development (general)

Developmental intervention should begin as soon as ID is suspected. Children 0-3 years of age may receive services from Early Intervention programs; local school districts serve children over age 3. For ID with vision or hearing impairment, special programs and schools may also be available.

Specialty Collaborations & Other Services

Developmental - Behavioral Pediatrics (see NM providers [2])

Developmental pediatricians can periodically evaluate a child's developmental progress and determine an ongoing plan for educational needs.

Developmental Assessments (see NM providers [105])

Developmental evaluations assess a child for typical versus atypical development in multiple domains.

Early Intervention for Children with Disabilities/Delays (see NM providers [34])

Early Intervention programs help identify and improve developmental outcomes in early childhood for babies and toddlers with ID or other disabilities.

Learning/Education/Schools

The medical home should assist families of children with ID in working with preschool and school systems to ensure appropriate accommodations, reasonable goal setting, and optimal support. All schoolchildren with ID should have an Individualized Education Plan (IEP) that includes the child's education goals, which should be achieved in the least restrictive environment depending on the child's IQ level and social abilities. IEPs are best developed with input from all the relevant disciplines - psychology, special education, speech therapy, occupational therapy - as well as from the family, teachers, and physicians. See the Portal's School Accommodations: IEPs & 504s section for detailed information about school-based services, legislation, and collaborating with educators written for medical home providers.

Specialty Collaborations & Other Services

School Districts (see NM providers [90])

School districts are the contact point for evaluation and determination of services for children who qualify for an IEP. Typically, school districts provide services for eligible children ages 3-21.

Mental Health/Behavior

Many children with ID will also have a psychiatric diagnosis. The diagnoses are similar to those found in typically developing children (affective disorders, attention deficit-hyperactivity disorder, obsessive-compulsive disorder, etc.), although they may be harder to diagnose as the individual’s language skills are often decreased. A diagnosis might, therefore, need to be based on "observable behavioral symptoms.” [Szymanski: 1999] Behavior problems should be actively explored because parents may not raise these issues within the medical home.
Externalizing behaviors, including aggression and Self-injurious Behavior, require a thoughtful history and physical exam looking for medical causes for disruptions of behavior (poor sleep, gastroesophageal reflux, dental caries, ear infection) and environmental causes (new aide at school, social isolation, new sibling, etc). Once these issues have been investigated, behavioral analysis and behavioral intervention are recommended.
Medication management of behaviors should only be considered after the previous recommendations have been instituted. Consultation with developmental pediatrics or child psychiatry is recommended before considering the use of antipsychotic medication. Often, phone consultation is available to primary care providers if medication is being considered. In general, medications should be started at low doses and titrated gradually.
Evaluating sustained and focused attention and impulse control is important since treating attention problems behaviorally and/or pharmacologically might maximize the child's potential by helping him/her to be more cognitively "available" for instruction and intervention. Such evaluation should be performed by specialists and may include assessment of speech, language, gross and fine motor development, social and emotional responsiveness, play imitation, non-verbal communication, attention and impulse control, intelligence, learning abilities, and more. An interdisciplinary approach is recommended for management, including professionals from social work, child psychology, developmental pediatrics, and child psychiatry, in addition to primary care physicians and educators when possible.

Specialty Collaborations & Other Services

Psychiatry/Medication Management (see NM providers [3])

Consider a referral to child psychiatry, particularly if medication is being considered.

Pediatric Physical Medicine & Rehabilitation (see NM providers [3])

PM&R physicians may have expertise in behavior management.

General Counseling Services (see NM providers [10])

Child psychologists may help the child and family with behavior management, counseling, and support.

Social Workers (see NM providers [0])

Social workers may help the child and family with counseling and assist with access to mental health resources.

Sleep

Children with ID, particularly those with autistic features, often have great difficulty maintaining a normal sleep schedule. Sleep disruption may cause additional attention and learning problems for the child and disrupt the entire family. Sleep problems in children with ID may not fit the common sleep disruption patterns seen in typically developing children, and they may be difficult to manage. Asking parents to keep a sleep record for one to several weeks may help in understanding the obstacles. A printable sleep record and 1-page questionnaire can be found at Sleep History Questionnaire (PDF Document 20 KB). See Sleep Issues for pages about medications and behavioral tips to improve sleep.
If a child with ID has difficulty sleeping, look for signs and symptoms of underlying medical problems (e.g., gastroesophageal reflux, dental caries) and obstructive sleep apnea (obesity, large tonsils, loud snoring). A sleep study may lead to diagnosis of a causative factor, such as seizures, apnea, or restless leg syndrome, which have potential treatments. Nonspecific treatments, such as melatonin or sleep medications, may also be useful.

Specialty Collaborations & Other Services

Sleep Disorders (see NM providers [0])

Sleep evaluations and treatment with sleep hygiene methods, breathing devices, and medications may be helpful.

Pediatric Otolaryngology (ENT) (see NM providers [11])

Surgery may be necessary if adenoids and tonsils are causing obstructive sleep apnea.

Dental

Poor oral health can lead to pain, difficulty eating, sleep disturbance, and decreased self-esteem, all of which can dramatically impact an individual's quality of life. Dental caries and periodontal disease are among the most common secondary conditions affecting people with ID. Although individuals with ID develop cavities at about the same rate as typically developing children, they are less likely to have them treated and are more likely to develop gingivitis and other periodontal disorders. [Anders: 2010]
Two subgroups at especially high risk for oral health problems are people with Down syndrome and people unable to cooperate for routine dental care. [Anders: 2010] Children with genetic syndromes or other diagnoses that are known to be associated with ID have a relatively high incidence of enamel hypoplasia and delayed eruption. Children with ID may have problems with tongue-thrust and bruxism and may demonstrate oral self-injurious behavior. The medical home should inquire about dental problems and refer to dentists comfortable with this population. Oral Care for People with Disabilities (National Institute of Dental and Craniofacial Research) provides information for people of all ages with disabilities and dental care. Also, see Dental and Oral Health Screening and Oral Health.

Specialty Collaborations & Other Services

General Dentistry (see NM providers [12])

These dental providers have expressed an interest in caring for children with special health care needs and may help patients accept routine care, treat issues related to underlying congenital or developmental anomalies, and treat periodontal disease.

Pediatric Dentistry (see NM providers [6])

Children with ID should be followed by a pediatric dentist from early in life. These dentists have formal training in pediatric dentistry, including those children with special health care needs.

Nutrition/Growth/Bone

Obesity is a significant health risk in individuals with ID, particularly as they reach adolescence. This risk increases with age. Please see Obesity in Children &Teens and Obesity in Children for screening and management information.

Specialty Collaborations & Other Services

Dieticians and Nutritionists (see NM providers [1])

The individual and his/her family may be helped by a referral to a nutritionist in the childhood years before this becomes an ongoing problem.

Maturation/Sexual/Reproductive

The medical home should discuss sexuality and reproduction with adolescents with ID in a manner that is appropriate to their cognitive level and their parents' values. Children and youth with ID often receive inadequate and much-delayed information about maturation and sex. Barriers include:
  • Negative attitudes about the sexuality of these individuals [McCabe: 1993]
  • The assumption that teens with disabilities do not need this information
  • The lack of available sex education specific to people with disabilities
  • The presence of intellectual impairment that might complicate the understanding of the sex education material
  • Concerns about sexual exploitation in this population - individuals with ID are more likely to be abused than those without ID [Mansell: 1998]
  • Body image/self-esteem concerns on the part of the adolescents
With onset of menses, adolescent girls with ID may experience difficulties managing hygiene and experience dysphoria/irritability/cramping or heavy periods. Traditionally, Depo-Provera has been used to suppress menstruation, but it may be associated with decreased bone mineralization. [Walsh: 2008] [Tolaymat: 2007] [Kaunitz: 2008] Skipping placebos when taking oral contraceptives may be successful for many adolescents, although spotting often occurs during the initial 6-month period. Intrauterine devices that release small amounts of progesterone locally may also be an option. For more information, see Sexuality & Children with Disabilities and Contraception & Menstrual Management.

Specialty Collaborations & Other Services

Gynecology: Pediatric/Adolescent; Special Needs (see NM providers [0])

Providers on this list have expressed interest in caring for girls and adolescents with special health care needs.

Transitions

Start transition planning early (generally around age 12) and include discussions about financial planning, how the individual will support him/herself, and where the individual will live. Assuring access to social security income and Medicaid can be critical – families should be encouraged to use a financial planner or lawyer familiar with individuals with disability. If necessary, guardianship will need to be applied for before the individual turns 18. Further information can be found at:
No Related Issues were found for this diagnosis.

Ask the Specialist

Will insurance pay for genetic testing?

Not all health plans in the US will cover genetic testing, regardless of who orders it or the nature of the encounter during which it is ordered (i.e., inpatient vs. outpatient). Typically, the medical genetics team has expertise and experience in payment for genetic testing.

Should I order the genetic testing or wait until patient is seen by genetics?

In a nondysmorphic patient with GDD/ID of unknown etiology, chromosomal microarray should be performed, but wait until the child is seen by genetics or neurology (in patients with neurological symptoms or seizures) unless the medical home is comfortable providing assistance with preauthorizing the testing and discussing the results with the family. Genetic counseling is also recommended whenever performing any genetic test. Any abnormalities should be reviewed with the help of a medical geneticist.

Should I perform imaging prior to consulting neurology or a developmental pediatrician?

This is certainly reasonable in the setting of abnormal head size, focal findings on neurologic exam, or extrapyramidal signs. Imaging may also be pursued in cases of intractable epilepsy or focal seizures, but these patients will usually already be seeing a neurologist. [Moeschler: 2014] In a patient <8 years of age who would need sedation in order to have imaging performed, it is reasonable to consult neurology first. It is also recommended to perform imaging at a center that has specialty in neuroradiology or pediatric neuroradiology whenever possible. MRI brain without contrast is the preferred study except where a concern for craniosynostosis exists.

Resources for Clinicians

On the Web

American Association on Intellectual and Developmental Disabilities
Promotes progressive policies, sound research, effective practices and universal human rights for people with intellectual and developmental disabilities.

Developmental Disabilities (CDC)
Information about developmental disabilities, including facts, research, articles, multimedia, and tool; Centers for Disease Control.

Intellectual Disability (ASHA)
Comprehensive information on intellectual disability, including signs and symptoms, incidence and prevalence, causes, assessment, and treatment; American Speech-Language-Hearing Association.

Helpful Articles

PubMed search for intellectual disability in children, last 2 years.

van Karnebeek CD, Stockler S.
Treatable inborn errors of metabolism causing intellectual disability: a systematic literature review.
Mol Genet Metab. 2012;105(3):368-81. PubMed abstract

Bass N, Skuse D.
Genetic testing in children and adolescents with intellectual disability.
Curr Opin Psychiatry. 2018;31(6):490-495. PubMed abstract

Clinical Tools

Assessment Tools/Scales

Ages and Stages Questionnaire (ASQ-3)
Parent-completed, age-specific questionnaires that screen for developmental delays in children between 1 month and 5½ years old; available for purchase.

Parent's Evaluation of Developmental Status (PEDS) site
PEDS and PEDS:DM provide 5-minute screenings, longitudinal surveillance, and triage for developmental as well as behavioral/social-emotional/mental health problems. Can be completed by parent self-report, interview, or administered directly to children; available for a fee.

Questionnaires/Diaries/Data Tools

Sleep History Questionnaire (PDF Document 20 KB)
A 14-day sleep tracker and 1-page questionnaire about sleep routines and behavior.

Resources for Patients & Families

Information on the Web

Forms for Education
Descriptions and links to forms that can be adapted for states and Local Education Authorities (LEAs), usually school districts, or charter schools. Topics include evaluation and service recommendations, special dietary needs, medication administration, and authorization to release information; Medical Home Portal.

A Family Handbook on Future Planning (ARC)
Helps families develop a plan that provides personal, financial, and legal protections for their children with cognitive, intellectual, or developmental disabilities after the parents either die or can no longer provide care; a publication of The Arc of the United States and the Rehabilitation Research and Training Center (RRTC) on Aging with Developmental Disabilities.

Intellectual Disability (MedlinePlus)
Information for families that includes description, frequency, causes, inheritance, other names, and additional resources; from the National Library of Medicine.

Learn the Signs Act Early (CDC)
Offers many tools, videos, lists, learning materials, and a developmental Milestone Tracker app (ages 2 months to 5 years); Centers for Disease Control and Prevention.

National & Local Support

The Arc
A national, community-based organization advocating for people with intellectual and developmental disabilities and their families.

Center for Parent Information and Resources
A large resource library related to children with disabilities. Locate organizations and agencies within each state that address disability-related issues.

A Guide to the Individualized Education Program (DOE)
Archived Information. Gives a detailed guide to the IEP process, along with information about special education and IEPs; U.S. Department of Education.

Individuals with Disabilities Education Act (IDEA)
Official U.S. Department of Education website of the Individuals With Disabilities Education Act including Part B (ages 3-21) and Part C (ages birth-2).

Studies/Registries

Clinical Trials in Intellectual Disabilities (clinicaltrials.gov)
Studies looking at better understanding, diagnosing, and treating this condition; from the National Library of Medicine.

Services for Patients & Families in New Mexico (NM)

For services not listed above, browse our Services categories or search our database.

* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.

Authors & Reviewers

Initial publication: May 2009; last update/revision: January 2021
Current Authors and Reviewers:
Author: Gary Nelson, MD
Reviewer: Sarah Winter, MD
Authoring history
2015: update: Meghan S Candee, MD, MScR
2009: first version: Lynne M. Kerr, MD, PhDA; Chuck Norlin, MDR
AAuthor; CAContributing Author; SASenior Author; RReviewer

Bibliography

American Psychiatric Association.
Diagnostic and Statistical Manual of Mental Disorders, DSM-5.
Fifth ed. Arlington, VA: American Psychiatric Association; 2013. 978-0-89042-554-1

American Psychiatric Association: DSM-5 Task Force.
Diagnostic and Statistical Manual of Mental Disorders.
Fifth ed. The American Psychiatric Publishing; 2013. http://dsm.psychiatryonline.org/doi/book/10.1176/appi.books.9780890425...

Anders PL, Davis EL.
Oral health of patients with intellectual disabilities: a systematic review.
Spec Care Dentist. 2010;30(3):110-7. PubMed abstract

Bass N, Skuse D.
Genetic testing in children and adolescents with intellectual disability.
Curr Opin Psychiatry. 2018;31(6):490-495. PubMed abstract

Battaglia A, Carey JC.
Diagnostic evaluation of developmental delay/mental retardation: An overview.
Am J Med Genet C Semin Med Genet. 2003;117(1):3-14. PubMed abstract

Battaglia A, Doccini V, Bernardini L, Novelli A, Loddo S, Capalbo A, Filippi T, Carey JC.
Confirmation of chromosomal microarray as a first-tier clinical diagnostic test for individuals with developmental delay, intellectual disability, autism spectrum disorders and dysmorphic features.
Eur J Paediatr Neurol. 2013;17(6):589-99. PubMed abstract

Chapman M, Iddon P, Atkinson K, Brodie C, Mitchell D, Parvin G, Willis S.
The misdiagnosis of epilepsy in people with intellectual disabilities: a systematic review.
Seizure. 2011;20(2):101-6. PubMed abstract

Curry CJ, Stevenson RE, Aughton D, Byrne J, Carey JC, Cassidy S, Cunniff C, Graham JM Jr, Jones MC, Kaback MM, Moeschler J, Schaefer GB, Schwartz S, Tarleton J, Opitz J.
Evaluation of mental retardation: recommendations of a Consensus Conference: American College of Medical Genetics.
Am J Med Genet. 1997;72(4):468-77. PubMed abstract / Full Text
A consensus statement regarding a rational clinical approach to a child with intellectual disability including history, physical exam and recommended testing.

Engbers HM, Berger R, van Hasselt P, de Koning T, de Sain-van der Velden MG, Kroes HY, Visser G.
Yield of additional metabolic studies in neurodevelopmental disorders.
Ann Neurol. 2008;64(2):212-7. PubMed abstract

Fan Y, Wu Y, Wang L, Wang Y, Gong Z, Qiu W, Wang J, Zhang H, Ji X, Ye J, Han L, Jin X, Shen Y, Li F, Xiao B, Liang L, Zhang X, Liu X, Gu X, Yu Y.
Chromosomal microarray analysis in developmental delay and intellectual disability with comorbid conditions.
BMC Med Genomics. 2018;11(1):49. PubMed abstract / Full Text

Kaunitz AM, Arias R, McClung M.
Bone density recovery after depot medroxyprogesterone acetate injectable contraception use.
Contraception. 2008;77(2):67-76. PubMed abstract

Mansell S, Sobsey D, Moskal R.
Clinical findings among sexually abused children with and without developmental disabilities.
Ment Retard. 1998;36(1):12-22. PubMed abstract

McCabe MP.
Sex education programs for people with mental retardation.
Ment Retard. 1993;31(6):377-87. PubMed abstract

Moeschler JB.
Genetic evaluation of intellectual disabilities.
Semin Pediatr Neurol. 2008;15(1):2-9. PubMed abstract

Moeschler JB, Shevell M.
Comprehensive evaluation of the child with intellectual disability or global developmental delays.
Pediatrics. 2014;134(3):e903-18 (reaffirmed 2020). PubMed abstract / Full Text
An AAP Clinical Report that provides guidance for primary care clinicians assisting families in preparing for a genetic evaluation; reaffirmed 2020.

Mueller S, Sherr EH.
The importance of metabolic testing in the evaluation of intellectual disability.
Ann Neurol. 2008;64(2):113-4. PubMed abstract

Oeseburg B, Dijkstra GJ, Groothoff JW, Reijneveld SA, Jansen DE.
Prevalence of chronic health conditions in children with intellectual disability: a systematic literature review.
Intellect Dev Disabil. 2011;49(2):59-85. PubMed abstract

Sattler, J.
Assessment of Children.
Third Edition ed. San Diego: Jerome M. Sattler Publisher; 1988. 9780961820978

Shevell M, Ashwal S, Donley D, Flint J, Gingold M, Hirtz D, Majnemer A, Noetzel M, Sheth RD.
Practice parameter: evaluation of the child with global developmental delay: report of the Quality Standards Subcommittee of the American Academy of Neurology and The Practice Committee of the Child Neurology Society.
Neurology. 2003;60(3):367-80. PubMed abstract / Full Text

Stevenson RE, Schwartz CE.
X-linked intellectual disability: unique vulnerability of the male genome.
Dev Disabil Res Rev. 2009;15(4):361-8. PubMed abstract

Stojanovic JR, Miletic A, Peterlin B, Maver A, Mijovic M, Borlja N, Dimitrijevic B, Soldatovic I, Cuturilo G.
Diagnostic and Clinical Utility of Clinical Exome Sequencing in Children With Moderate and Severe Global Developmental Delay / Intellectual Disability.
J Child Neurol. 2020;35(2):116-131. PubMed abstract

Szymanski L, King BH.
Practice parameters for the assessment and treatment of children, adolescents, and adults with mental retardation and comorbid mental disorders. American Academy of Child and Adolescent Psychiatry Working Group on Quality Issues.
J Am Acad Child Adolesc Psychiatry. 1999;38(12 Suppl):5S-31S. PubMed abstract
A review of mental health disorders in the DD/MR population. Although possibly more frequent in this population, psychiatric disorders are essentially the same as in normally developing children; however, behavioral observations are very important due to decreased verbal skills in this population.

Tolaymat LL, Kaunitz AM.
Long-acting contraceptives in adolescents.
Curr Opin Obstet Gynecol. 2007;19(5):453-60. PubMed abstract

van Karnebeek CD, Stockler S.
Treatable inborn errors of metabolism causing intellectual disability: a systematic literature review.
Mol Genet Metab. 2012;105(3):368-81. PubMed abstract

Walsh JS, Eastell R, Peel NF.
Effects of Depot medroxyprogesterone acetate on bone density and bone metabolism before and after peak bone mass: a case-control study.
J Clin Endocrinol Metab. 2008;93(4):1317-23. PubMed abstract

Zablotsky B, Black LI, Blumberg SJ.
Estimated Prevalence of Children With Diagnosed Developmental Disabilities in the United States, 2014-2016.
NCHS Data Brief. 2017(291):1-8. PubMed abstract

Zablotsky B, Black LI, Maenner MJ, Schieve LA, Danielson ML, Bitsko RH, Blumberg SJ, Kogan MD, Boyle CA.
Prevalence and Trends of Developmental Disabilities among Children in the United States: 2009-2017.
Pediatrics. 2019;144(4). PubMed abstract / Full Text