Studies with a mouse model of Down's syndrome may reveal the elusive origins of this common disorder.

Although long known to be the result of an extra copy of chromosome 21 (trisomy 21), the detailed mechanisms of the condition remain unclear. Recently, Professor Elizabeth Fisher and colleagues developed a mouse model carrying an almost complete extra copy of human chromosome 21. The mouse shows many of the symptoms seen in the human condition.

With new programme grant funding, Professor Fisher and Dr Victor Tybulewicz of the National Institute for Medical Research will use these mice to dissect the molecular basis of Down's syndrome. They plan to analyse the physiological defects of the mice in detail, and see how they are affected by specific changes to the extra human chromosome, such as the presence or absence of certain genes.

The studies should shed light on the key gene (or genes) responsible for the many different symptoms seen in Down's syndrome.

External links

• Down's syndrome recreated in mice (BBC news, 22 September 2005)