Down's syndrome

Down's syndrome is the most common genetic cause of cognitive or intellectual disability, with a prevalence of 1 in 800 births worldwide.

Characteristic physical features include brachycephaly with a flat occiput; epicanthal folds and upslanting palpebral fissures; Brushfield spots in the iris; low nasal bridge; low-set ears; broad neck; and small hands with transverse crease.

Individuals with Down's syndrome have a higher frequency of congenital and acquired medical conditions, including congenital heart defects and audiological, vision, gastrointestinal, haematological, and thyroid issues.

Global developmental delay is common; however, cognitive abilities vary greatly, with IQ ranging from mild to moderate intellectual disability. Behavioural difficulties, if present, tend to be age-related (e.g., hyperactivity and impulsiveness in younger children; withdrawal and anxiety in older adolescents).

Early interventional therapies (e.g., speech therapy, physiotherapy, occupational therapy) and individualised educational programmes/resources are essential to maximise the potential of a person with Down's syndrome.

Down's syndrome (DS), or trisomy 21, is the most common genetic form of intellectual disability, occurring in 1 in 800 births worldwide.[1]Bull MJ. Down syndrome. N Engl J Med. 2020 Jun 11;382(24):2344-52. http://www.ncbi.nlm.nih.gov/pubmed/32521135?tool=bestpractice.com In addition to having characteristic physical features, short stature, and hypotonia, individuals with DS have a distinctive cognitive and behavioural profile. They also have a higher frequency of associated medical conditions, including congenital heart defects, and gastrointestinal, thyroid, haematological, audiological, and visual abnormalities.