Intellectual Disability

Description

Other Names

Mental retardation
Static encephalopathy

Diagnosis Coding

ICD-9

319, Intellectual developmental disorder

DSM-5 and ICD-10

F70, Intellectual disability (ID), aka intellectual developmental disorder, Mild

F71, ID, moderate

F72, ID, severe

F73, ID, profound

ICD-10 Coding Reference for Intellectual Disability provides further coding details. The DSM-5 codes (above) reflect the American Psychiatric Association update in 2014; an explanation of specific changes can be found at DSM-5 Coding Update Supplement (APA) (PDF Document 185 KB).

Description

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] While there is no treatment for ID, some of the conditions causing it (e.g., metabolic errors or hypothyroidism) can be treated and much can be done to limit secondary disabilities, to optimize functional abilities, and to assist the affected child and his/her family in adapting to the condition.

Prevalence

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

Genetics

Many etiologies for ID are genetic. When possible, all children with ID without a known etiology should have a genetic evaluation.

Prognosis

Measures of intellect and adaptive behavior are somewhat predictive of 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. Individuals with severe and profound ID tend to have shortened life expectancies as well, often due to the conditions causing ID.

Roles Of The Medical Home

A diagnosis of ID is important to allow the family to begin making realistic plans for the education and future of the child. The diagnosis also allows the child to qualify for early intervention, special educational services, and, depending on the financial status of the family, entitlement programs such as disability services.

The medical home can:
  • Schedule health maintenance visits frequently enough to be proactive about 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 quality for government or school sponsored services, such as OT, PT, or speech therapy.
  • 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. (Programs for recreational and leisure opportunities are listed toward the bottom of the Intellectual Disability, Services & Other Resources section of the module.)

Practice Guidelines

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

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

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

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

Nevels RM, Dehon EE, Alexander K, Gontkovsky ST.
Psychopharmacology of aggression in children and adolescents with primary neuropsychiatric disorders: a review of current and potentially promising treatment options.
Exp Clin Psychopharmacol. 2010;18(2):184-201. PubMed abstract

Clinical Assessment

Overview

Important steps in the clinical assessment of a child with ID include:
  1. Suspicion of ID, which is often prompted by parent interview and/or direct observation of the child, should be confirmed with norm-referenced testing for IQ and adaptive functioning. The Portal's issue page on Psychometric Testing (general) provides lists of possible tests for IQ/development, adaptive behavior, achievement, and behavior.
  2. Treatable diagnoses that might mimic ID, such as severe auditory or visual impairment or neurologic disorders, must be ruled out.
  3. Identification of the etiology, if possible, through medical history (including 3 generations) and/or 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 for ID may be treatable. [Engbers: 2008] [Mueller: 2008] Knowing the cause can be helpful in determining prognosis and risk of recurrence in the family and for predicting the child's ability to live independently in the future.
  4. Determining the severity of ID, with psychometric and adaptive function testing can be helpful in prognosis for independent living.
  5. Determining 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.
Opinion in the literature is mixed regarding the earliest age at which a diagnosis of ID is reasonably possible. It is usually possible in the preschool years, earlier for more severe cases, but not reliably until age 5. [Shevell: 2003]

Screening

For The Condition

Developmental screening, an important component of routine well-child care, should identify many children with developmental delay (DD) 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 the following degrees of intellectual functioning:
  • Borderline
  • Mild
  • Moderate
  • Severe
  • Profound

Differential Diagnosis

Autism spectrum disorders, specific language problems, and hearing problems may be confused with ID in young children, or may coexist with ID. ID can also be confused with developmental delay or static encephalopathy.

ID should only be diagnosed when there is clear evidence that cognitive abilities and adaptive behavior are significantly below average and that, although the individual might make progress in learning, they will always be significantly below average. This excludes individuals with conditions that might be temporary (e.g., the convalescent period after a brain insult such as meningitis or trauma, the response to early neglect, or children soon after foreign adoption). It also excludes the very young where 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 "catch up" to their peers.

Medical Conditions Causing Intellectual Disability

Out of the hundreds of known causes of ID, half are thought to be exogenous (e.g., prenatal exposure to infection or toxins); the other half are likely due to genetic causes. [Battaglia: 2003] 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 non-specific 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
  • Post-natal infection, head injury, abuse/neglect, malnutrition, lead/mercury exposure
The likelihood of finding an etiology for ID in a given child is not correlated with the severity of ID. [Battaglia: 2003]

Comorbid Conditions

Co-morbid conditions include Childhood Absence Epilepsy, Cerebral Palsy, anxiety disorders, oppositional behavior disorders, Attention Deficit Hyperactivity Disorder (ADHD), and Autism Spectrum Disorder. [Oeseburg: 2011]

Pearls & Alerts

Children with autism may have normal intelligence

IQ tests on children with autism may underestimate IQ because the testing is often language based.

Misdiagnosis of seizures possible

Although the clinician should be alert for seizures, physiological events, behaviors, and even syndrome features may be mistaken for seizures. [Chapman: 2011]

DD vs. ID

The term “developmental delay” (DD) 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. Delays in development, especially those that are mild, may be transient and lack predictive reliability for ID or other developmental disabilities.

History & Examination

Since knowledge about genetic etiologies is increasing so rapidly, reconsideration of an inconclusive original diagnosis, or lack of etiologic diagnosis, is warranted. Periodic re-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.

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 Or 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 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

Current & Past Medical History

Ask about decreased growth or overgrowth, infection, head injury, abuse/neglect, malnutrition, unusual eye movements, concern for seizures, motor abnormalities (asymmetric tone/strength/muscle use), social skills, lead/mercury exposure, hearing and vision problems, and previous testing.

Parents may not realize that sleep issues are potentially treatable and the medical home should asked about their child’s sleep habits, history of snoring, and any daytime sleepiness at well-child visits. The Sleep History Questionnaire (PDF Document 20 KB) has a printable sleep log and one page of mostly yes/no questions about sleep routines and behavior.

Developmental & Educational Progress

Ask about time of achievement of developmental milestones. 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. In addition to asking the child and family directly, reports from early intervention or school including evaluations and report cards, are helpful to monitor progress in this area.

Ask about behavior problems and self-injurious behaviors; mental health problems are frequent in children and adolescents with ID.

Maturational Progress

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

Social & Family Functioning

Ask about family functioning, parental jobs, financial resources for caring for a child with ID, and family support systems. (The end of the Intellectual Disability, Services & Other Resources section has links to financial help, adaptive recreation, and other helpful services.)

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 fontanels (FTT, compare to parents), asymmetry?

Skin

Look for the presence of abnormal textures, hyper- or hypopigmentation, eczema, Wood's lamp findings, hemangiomata.

HEENT

Note head size and shape. Look at facies - similar to family members? 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.

Mouth/Teeth

Check for caries and enamel defects. Children with ID may have difficulty with oral hygiene and may not have access to dentists comfortable with their care.

Abdomen

Hepatosplenomegaly

Genitalia

Size, structure

Extremities/Musculoskeletal

Look for single palmar creases, clinodactyly, size of hands/feet, nail abnormalities, presence of contractures, and hyperextensibility.

Neurologic Exam

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

Testing

Sensory Testing

Hearing and vision testing is 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

The percentage of people with identifiable metabolic disorders as of cause of ID ranges from 1%-5%. Although newborn screening identifies many of these disorders, further metabolic testing maybe 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%. When an etiology cannot be identified, an MRI may still be cost-effective as a once-in-a-lifetime test, particularly when results might be important in family planning and genetic counseling. The American Academy of Neurology and Child Neurology Society recommends neuro-imaging as part of an evaluation of the child with ID [Shevell: 2003], whereas the American College of Medical Genetics does not feel that neuroimaging should 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 otherwise 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 helpfulness of the information gained.

EEG should be performed when clinical seizures or a seizure syndrome are suspected.

Skeletal survey, other imaging may be recommended as part of a genetics consultation.

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 rate of a standard karyotype. [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, via an X-linked intellectual disability panel or MECP2, 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, but information about available tests for conditions associated with ID can be found at Genetic Disorders and ID (GeneTests).

Medical home providers should work closely and communicate clearly with the consulting geneticist when interpreting CMA test results, particularly when variants of unknown significance are identified. [Moeschler: 2014] Findings may be pathogenic, benign, or of unknown significance.

Other Testing

A positive 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 (a.k.a. neuropsychological, neurocognitive or psychoeducational testing) is critical to confirm the diagnosis, provide some idea of the child's prognosis, guide therapeutic interventions, and a diagnostic workup in some cases. See the Intellectual Disability, Services & Other Resources section for details on neuropsychological testing resources.

A sleep study should be performed if clinically indicated.

Subspecialist Collaborations & Other Resources

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, etc. based on the history and physical exam.

Pediatric Genetics (see Services below for relevant providers)

When a diagnosis of ID is confirmed, a genetic evaluation is recommended. Since knowledge of new genetic syndromes and new genetic testing is evolving rapidly, consider periodic reassessment of the child with unknown etiology. Genetic counseling may also be appropriate for the family.

Pediatric Metabolic Genetics (see Services below for relevant providers)

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 Services below for relevant providers)

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 & Rehab (see Services below for relevant providers)

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

Pediatric Ophthalmology (see Services below for relevant providers)

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 Pediatrics (see Services below for relevant providers)

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

Psychologist, Child-18 (see Services below for relevant providers)

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

Psychiatrist, Child-18 (see Services below for relevant providers)

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.

Neuropsychology (see Services below for relevant providers)

Assessment of functioning is particularly important when the child has neurological symptoms, such as brain injury or seizures. This process helps identify learning challenges, describe communication styles, and summarize a child’s strengths and weaknesses for the purpose of formulating a diagnosis and implementing modifications/interventions.

Sleep Studies/Polysomnography (see Services below for relevant providers)

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

Underlying condition can cause challenging behaviors

Check carefully for underlying medical conditions that 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 very 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 to evaluate for a potential CNS or metabolic cause for dysfunction.

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, and children over 3 are served by their local school districts. For some kinds of ID, special schools may also be available.

Subspecialist Collaborations & Other Resources

Developmental Pediatrics (see Services below for relevant providers)

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

Developmental Evaluation (see Services below for relevant providers)

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

Early Intervention Programs (see Services below for relevant providers)

Early Intervention programs are services to 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 Education & Schools section and for detailed information about school-based services, legislation, and collaborating with educators written for medical home providers. Also, see the Portal's page on Inclusion Models (general).

Subspecialist Collaborations & Other Resources

School Districts (see Services below for relevant providers)

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.

Behavior problems, especially aggression directed toward self or others, can cause tremendous difficulties for families. Problems with behavior often increase exponentially with adolescence. Self-injurious behaviors can include individuals hitting and biting themselves or causing themselves to gag, head banging, and chewing on extremities. In children without good communication skills, rule out potential medical causes of new self-injurious behaviors (such as dental caries, gastroesophageal reflux, ear infections, etc.) and environmental causes (e.g., a new aide at school, a new sibling, etc.) Social isolation caused by ID may add to the incidence of affective disorders. If these factors are ruled out, behavioral management should be tried.

Although use of antipsychotics to manage aggression is controversial [Tsiouris: 2010], management will generally involve medication and behavioral management techniques. The medical home should not be hesitant to use medications, even if temporary, to help manage difficult behavior or situations that need immediate help. Medications may include antipsychotics, atypical antipsychotics, serotonin specific reuptake inhibitors, mood stabilizers, benzodiazepines, stimulants, and clonidine. Risperidone may be especially helpful in these children and adolescents, and has been approved by the FDA for this use. [Shea: 2004] Medications should be started at low doses and raised very gradually. A referral to a child psychiatrist familiar with children with ID can help with this process. If access to psychiatry is not possible, consider a phone consultation if not familiar with medications for problem behavior.

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, and child psychiatry, in addition to primary care physicians and educators when possible. See the Portal's Behavioral Medication Information and Aggression and Self-Injurious Behavior (ddhealthinfo) for more information.

Subspecialist Collaborations & Other Resources

Psychiatrist, Child-18 (see Services below for relevant providers)

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

Pediatric Physical Medicine & Rehab (see Services below for relevant providers)

PM&R physicians may have expertise in behavior management.

Psychologist, Child-18 (see Services below for relevant providers)

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

Social Work (see Services below for relevant providers)

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).

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. See the Portals Medications for Sleep (general) and Sleep Problems (general) for further information.

Subspecialist Collaborations & Other Resources

Pediatric Sleep Medicine (see Services below for relevant providers)

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

Pediatric Otolaryngology (see Services below for relevant providers)

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 have a dramatic impact on 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.

Subspecialist Collaborations & Other Resources

General Dentistry for Children (see Services below for relevant providers)

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

Pediatric Dentistry (see Services below for relevant providers)

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.

Subspecialist Collaborations & Other Resources

Nutrition/Dietary (see Services below for relevant providers)

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 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 understanding of sex education material
  • Concerns about sexual exploitation in this population, as 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 feelings of 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 a full discussion, see Sexuality and People with Disabilities (PDF Document 257 KB).

Subspecialist Collaborations & Other Resources

Gynecology (Ped/Adol, Special Needs) (see Services below for relevant providers)

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

Transitions

Start transition planning early 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 when the individual turns 18. Further information can be found at Transitions (National Center for Medical Home Implementation), A Guide for Health Care Providers: Transition Planning for Adolescents with Special Health Care Needs and Disabilities, and the Portal's Transition to Adulthood section.

Frequently Asked Questions

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).

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. Patients/families may want to check with their insurance company to see if coverage is at all dependent on who orders the testing. Any abnormalities should be reviewed with the help of a medical geneticist.

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

Yes, particularly in the setting of abnormal head size, focal findings on neurologic exam, extrapyramidal signs, intractable epilepsy, or focal seizures. [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.

Issues Related to Intellectual Disability

Clinical Assessment

Psychometric Testing

Learning/Education/Schools

Inclusion Models

Mental Health/Behavior

Behavioral Medication Information

Resources

Information for Clinicians

Information that is more specific may be available when the etiology for ID is known.

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

Developmental Disabilities Information (ddhealthinfo.org)
Information and resources about developmental disabilities for clinicians that includes clinical practice considerations for related conditions and information about related issues (communication, dental, mental health, CAM); University of California San Diego, School of Medicine.

Developmental and Behavioral Pediatrics (AAP)
Information for professionals interested in child development and behavior. Contains practice management resources, upcoming educational events, relevant policy statements, and high-quality links; American Academy of Pediatrics.

Genetic Disorders and ID (GeneTests)
List of disorders that often result in ID and direct links to phenotype-gene relationship and clinical synopsis on Online Mendelian Inheritance in Man (OMIM) List of disorders that often result in ID and direct links to phenotype-gene relationship and clinical synopsis on Online Mendelian Inheritance in Man (OMIM) and GeneReview.

Genetics in Primary Care Institute (AAP)
The goal of this site is to increase collaboration in the care of children with known or suspected genetic disorders. Includes health supervision guidelines and other useful resources; a collaboration among the Health Resources & Services Administration, the Maternal and Child Health Bureau, and the American Academy of Pediatrics.

Helpful Articles

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

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

Nevels RM, Dehon EE, Alexander K, Gontkovsky ST.
Psychopharmacology of aggression in children and adolescents with primary neuropsychiatric disorders: a review of current and potentially promising treatment options.
Exp Clin Psychopharmacol. 2010;18(2):184-201. 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

Clinical Tools

Assessment Tools/Scales

Ages and Stages Questionnaire: Developmental (ASQ-3) (Brookes)
Parent-completed questionnaire of about 30 age-related questions that screens for developmental delays between one month and 5½ years. Available for purchase from Brookes Publishing Company.

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.

Developmental Screening Toolkit (Children's Hospital Boston)
Provides education for clinicians interested in implementing developmental screening in their practice and a comparison of screening tools.

Patient Education & Instructions

Intellectual Disability Fact Sheet (English & Spanish) (CDC)
One-page fact sheet for families who may be concerned that their child has intellectual disability; Centers for Disease Control and Prevention.

Patient/Family Questionnaires/Diaries/Data Tools

Sleep History Questionnaire (PDF Document 20 KB)
Sleep log and 1-page questionnaire about sleep routines and behavior.

Information & Support for Families

Family Diagnosis Page

Information on the Web

Financing Your Child's Healthcare (MHP)
Information, services, and resources that may help offset some of the medical costs of caring for your child with special health care needs; Medical Home Portal.

Care Notebook (MHP)
The care notebook helps keep track of appointments, resources, labs, medications, tests, care providers, and more. Download the complete notebook, compile in your own binder, or download separate forms; Medical Home Portal.

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; The Arc.

Intellectual Disability (MedlinePlus)
Overview of the causes, symptoms, and treatment of ID; from the National Library of Medicine and National Institutes of Health.

Learn the Signs. Act Early (CDC)
A CDC program to address the importance of early identification of developmental delay and disability. Early intervention (before school age) can have a significant impact on a child’s ability to learn new skills, as well as reduce the need for costly interventions over time; Centers for Disease Control and Prevention.

Support National & Local

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

Mutual Respect, Advocacy, and Understanding of Utah (MRAU)
Provides advocacy, education, newsletters, and conferences related to ID; helps families with guardianship information.

Center for Parent Information and Resources
A large resource library related to children with disabilities. Parent Centers in every state provide training to parents of children with disabilities.

Services for Patients & Families

Developmental Evaluation

See all Developmental Evaluation services providers (55) in our database.

Developmental Pediatrics

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Early Intervention Programs

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General Dentistry for Children

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Gynecology (Ped/Adol, Special Needs)

See all Gynecology (Ped/Adol, Special Needs) services providers (21) in our database.

Neuropsychology

See all Neuropsychology services providers (33) in our database.

Nutrition/Dietary

See all Nutrition/Dietary services providers (53) in our database.

Pediatric Dentistry

See all Pediatric Dentistry services providers (57) in our database.

Pediatric Genetics

See all Pediatric Genetics services providers (5) in our database.

Pediatric Metabolic Genetics

See all Pediatric Metabolic Genetics services providers (2) in our database.

Pediatric Neurology

See all Pediatric Neurology services providers (10) in our database.

Pediatric Ophthalmology

See all Pediatric Ophthalmology services providers (8) in our database.

Pediatric Otolaryngology

See all Pediatric Otolaryngology services providers (9) in our database.

Pediatric Physical Medicine & Rehab

See all Pediatric Physical Medicine & Rehab services providers (8) in our database.

Pediatric Sleep Medicine

See all Pediatric Sleep Medicine services providers (3) in our database.

Psychiatrist, Child-18

See all Psychiatrist, Child-18 services providers (28) in our database.

Psychologist, Child-18

See all Psychologist, Child-18 services providers (151) in our database.

School Districts

See all School Districts services providers (46) in our database.

Sleep Studies/Polysomnography

See all Sleep Studies/Polysomnography services providers (8) in our database.

Social Work

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Special Needs Schools, Other

See all Special Needs Schools, Other services providers (10) in our database.

For other services related to this condition, browse our Services categories or search our database.

Authors

Author: Lynne M Kerr, MD, PhD - 5/2009
Reviewing Authors: Meghan Candee, MD - 6/2015
Chuck Norlin, MD - 5/2009
Content Last Updated: 6/2015

Bibliography

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

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

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 mental retardation 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

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. PubMed abstract / Full Text

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

Nevels RM, Dehon EE, Alexander K, Gontkovsky ST.
Psychopharmacology of aggression in children and adolescents with primary neuropsychiatric disorders: a review of current and potentially promising treatment options.
Exp Clin Psychopharmacol. 2010;18(2):184-201. 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

Shea S, Turgay A, Carroll A, Schulz M, Orlik H, Smith I, Dunbar F.
Risperidone in the treatment of disruptive behavioral symptoms in children with autistic and other pervasive developmental disorders.
Pediatrics. 2004;114(5):e634-41. PubMed abstract

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

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

Tsiouris JA.
Pharmacotherapy for aggressive behaviours in persons with intellectual disabilities: treatment or mistreatment?.
J Intellect Disabil Res. 2010;54(1):1-16. 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

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