Disabilities

Background on the type, severity and possible cause of the disability.

Christopher Walsh is aged 30, he has Down syndrome. He has had Down syndrome since birth, he had heart problems, he was born with Heart defects, he had surgery when he was 2 and they were able to fix the heart problems. Down syndrome is sometimes caused by an error in cell division called disjunction; there are two other types of chromosomal abnormalities, mosaicism and translocation, which are also implicated in Down syndrome, sometimes to a lesser extent.

Genes are grouped along rod like structures called chromosomes. Normally the nucleus of each cell contains 23 sets of chromosomes, half of which are inherited from each parent. Down syndrome can be transmitted from the mother or the father. In Down syndrome, the cells usually have not 46 but 47 chromosomes, the extra chromosome being a number 21. The excess genetic material, in the form the additional genes along the 21st chromosome, results in Down syndro...