Disorders/Conditions that have Intellectual Disabilities

Genetic mechanism with deletion of chromosome 15 as the most frequent cause; estimated prevalence 1 in 10,000 to 20,000. Up to 26% have no genetic cause and are diagnosed clinically.
Hypotonia and feeding problems within first 6 months followed by develop

angelman syndrome

Caused by mutations in the NIPBL, SMC1A, and SMC3 genes; estimated to affect 1 in 10,000 to 30,000 newborn infants.
Spasticity, intention tremor, seizure disorder (10% to 20%), microcephaly
Severe growth retardation; decreased bone age, small stature, sma

cornelia de lange

A rare chromosomal disorder (1 in 50,000 live births) caused by loss of chromosomal material from region 5p (5p12)
name comes from characteristic cat-like cry due to problems with larynx and CNS.
Hypotonia in early childhood, sometimes hypertonia later

cri du chat syndrome

One of the most common causes of prenatal infections in developed countries, with incidence estimated to be between 0.15% and 2.0%.
Cerebral palsy, seizure disorder, microcephaly (hearing problems), hepatomegaly


Caused by prenatal exposure to alcohol, the estimated prevalence of fetal alcohol syndrome is about 1%.
Fine motor and visual motor deficits, balance deficits
Minor facial abnormalities, joint anomalies with abnormal position or function, maxillary hypopl


The most common form of inherited mental retardation, it is primarily caused by expansion of a sequence in the FMR1 gene of the X chromosome
Poor coordination and motor planning, seizures
Connective tissue abnormalities, which may lead to congenital hip d

fragile X syndrome

Autosomal recessive storage disorder with lack of lysosomal hydrolase ?-l-iduronidase.
Joint contractures, clawlike deformities of hands, short fingers, thoracolumbar kyphosis, shallow acetabular and glenoid fossae, irregularly shaped bones

Hurler syndrome

Caused by a genetic deficiency of hypoxanthine-guanine phosphoribosyltransferase located on the X chromosome.
Hypotonia followed by spasticity and chorea, athetosis, or dystonia; compulsive self-injurious behavior

Lesch-Nyhan syndrome

Inherited metabolic disease, autosomal recessive disorder caused by mutation to the PAHgene. Treated with dietary means, enzyme therapy, and pharmaceutical supplementation. Occurs in 1 of 10,000 to 20,000 newborns. Neonates are screened for this. Progress

Phenylketonuria (PKU)

A chromosomal microdeletion disorder that occurs in 1 in 10,000 to 15,000 live births. It is the leading genetic cause of obesity
Severe hypotonia and feeding problems in infancy, excessive eating (usual onset 1-6 years) and obesity in childhood, poor fin


Definitive diagnosis is accomplished by mutation analysis on leukocyte DNA for the gene MECP2.
Deceleration in rate of head growth in infancy, gradual loss of acquired skills after 6 to 18 months of age, loss of purposeful hand skills, stereotypic hand mo

rhett syndrome

Caused by mutation or deletion of the elastingene at 7q11.23; it occurs in 1 in 20,000 live births
Mild neurologic dysfunction, hypotonia, hyperreflexia, cerebellar dysfunction
markedly outgoing personality, good communication skills. high levels of calci

Williams (elfin facies) syndrome 115Caused

what is the name of this adaptive behavior instrument?
Commonly used for older children to measure adaptive abilities. Results of a validity study indicated that the personal independence and social behavior scales of the tool demonstrated the largest dif

The AAMR Adaptive Behavior Scale-School (ABS-S:2)

what is the name of this adaptive behavior instrument?
currently under development by the AAIDD. This tool measures three domains of adaptive behavior identified by the AAIIDD: Conceptual Skills, Social Skills, and Adaptive Skills.

The Diagnostic Adaptive Behavior Scale (DABS)

what is the name of this adaptive behavior instrument?
Frequently used for older children. Administered as a questionnaire or rating form that asks about activities of daily living, cognition, language, play, and social competency.

Vineland Adaptive Behavior Scales

the vineland adaptive behavior scale can be used with what conditions?

- ID

A tool that is helpful for identifying the level of supports that adolescents and adults with intellectual disabilities and other developmental disabilities need for quality participation in society
The tool was normed with people age 16 to over 70 years

Supports Intensity Scale (SIS)