Day for Down’s syndrome

Today, 21 March (2009), is World Down’s Syndrome Day. The date was chosen because the condition is caused by trisomy 21 — the presence of a third copy of chromosome 21. This year also happens to be the 50th anniversary of the discovery that Down’s syndrome is caused by chromosome 21 trisomy.

Faulty cell division during gamete formation, usually in the ovaries of older women, results in an oocyte with either no chromosome 21 or two copies. Those oocytes without a chromosome 21 will die. However, those with two copies may be fertilised and the zygote will then have three copies.

(A small proportion of cases of Down’s have a different cause: during meiosis, part of the long arm of chromosome 21 in the gamete of either parent breaks off and becomes attached to another chromosome in a process known as translocation.)

People with Down’s Syndrome have characteristic facial features to varying degrees. They are described as gentle, loving and happy people, although there are varying problems with cognitive skills. Their life expectancy tends to be relatively short, although this is improving as medical interventions and care advance.

People have often concealed and sheltered Down’s Syndrome children, because of the shame felt in having such a child. A remarkable book, ‘The memory keeper’s daughter’ by Kim Edwards, set in 1960s Kentucky, describes how a doctor delivers his own wife’s twins. The boy is healthy but the girl has Down’s syndrome.

The doctor secretly gives the baby girl into the care of a nurse and tells his wife that the child has died. The little girl makes her own way in the world, cared for by the nurse who took part in the deception, and achieves much. She is eventually reunited with her brother. It is to be hoped that the situation is much better in our enlightened 21st century.

Early diagnosis of Down’s syndrome in utero will present parents with the heart-rending choice of whether to terminate the pregnancy or not. This is an intensely personal decision.

However, support for parents with Down’s Syndrome children is now more widely available, and media coverage has increased awareness of the many achievements that Down’s children can make. If proof were needed that their disability is not necessarily a limitation, the 2008 Paralympics was it.

Recently, the Merlins saw a performance staged by their grand-daughter’s ballet school. Most of the dancers were girls, but among the few boys was one with Down’s Syndrome. He was resplendent in his costume and obviously enjoyed taking part.

How times have changed, and very much for the better, in our attitudes to people with conditions such as Down’s.