Types of Down's Syndrome
There are three different types of Down’s Syndrome. Ninety-five per cent of people with Down’s Syndrome have the type known as standard trisomy 21. This type of Down’s Syndrome is always an accident of nature. It can happen to anyone and it is not known why it occurs.
Approximately one in 100 people have the second type of Down’s syndrome. They inherit the condition from their mother or father because of a genetic anomaly called a translocation.
The third type of Down’s syndrome, also rare, is known as Mosaic Down’s Syndrome, in which an extra chromosome 21 appears in only some of the cells.