Downs Syndrome
This is the commonest specific cause of learning disability. It occurs in 1 in 650 live births.
It’s caused by a chromosomal abnormality – addition of a third chromosome 21 [trisomy 21]
Intellectual impairment is always present. 85% have moderate or severe learning disability.
People with Downs syndrome have a characteristic facial appearance distinguished by small ears and eyes, a small head, large tongue and short stature.
Associated physical problems are common and include congenital heart defects, hypothyroidism, visual disorders including cataract, hearing impairment, obesity, epilepsy, instability of spinal joints in the neck, diabetes and coeliac disease, respiratory and other infections due to poor immunological defence mechanism, leukaemia and obstructive sleep apnoea Downs syndrome is associated with high rates of depression.
Emotional and behavioural disorders include over activity, mischievousness, stubbornness and lack of inhibition, which can put individuals at risk. Aggression and violence are rare.
Simple literacy skills may be developed by some, but usually with limited comprehension.
Speech and language problems are a particular feature, due to both intellectual and physical factors. The shape of the palate, small mouth cavity, relatively large tongue and tendency to nasal speech lead to poor pronunciation of words. Recurrent ear infections, causing intermittent and variable hearing impairment, commonly add to the difficulties. The speech may be insufficiently clear to be understood by strangers and in many cases real fluency is never achieved.
Understanding of relationships, both personal and in society at large, is limited. Emotional and social maturity are rarely achieved, and the risk of exploitation is high in adult life. Life expectancy is close to 50 years with 25% living beyond that age.
The limitation of reasoning ability is such that few are able to achieve full social independence, though most learn several self-care skills. Personal hygiene however may remain a problem e.g. menstrual hygiene, shaving.
Although a certain amount of independence may be attained eventually, this is usually only possible within a structured environment. A few individuals are however able to live independently with minimal support.
Most people with Downs Syndrome are able to walk by 5 years of age. The presence of a severe cardiac, respiratory, or other disorder may, of itself, give rise to mobility needs. When physical mobility has been established, independence may eventually be achieved on simple well-known routes but not, usually, in unfamiliar surroundings.
Some needs existing in childhood decrease as self-care skills are learned.
This is a slow process, which often continues into adult life. Needs persisting beyond school leaving, however, are likely to remain.
Cognitive decline and dementia similar to Alzheimer’ disease occurs 30-40 years earlier than the general population. It occurs in 25% of people with Downs Syndrome and results in gradual loss of self care skills.
Amended October 2012
