Down Syndrome

(also known as Trisomy 21, T21).

This syndrome was initially described by Dr John Langdon Down, a London based Physician in 1866. It is the most common pattern of malformation in humans with a birth incidence of 1:660. The vast majority are due to the inheritance of an additional chromosome 21 at the time of conception.

The risk of a mother having a child with Down syndrome increases with advancing age.

Indivduals with Down syndrome have a typical ‘Mongoloid’ facial appearance and 40% have significant cardiac abnormalities and tend to have an IQ level of 25-50.