A genetic explanation for why people with Down’s syndrome have a reduced incidence of solid cancers is reported in this week’s Nature. The findings identify potential targets for tumour prevention and therapy.

Down’s syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21. It’s been known for some time that individuals with Down’s syndrome get certain types of cancer less often than those without the condition, although until now little was known about why. Sandra Ryeom and colleagues show that having an extra copy of one of the genes located on chromosome 21, Dscr1, is sufficient to slow cancer growth in a mouse model. Dscr1 seems to work in conjunction with another chromosome 21 gene, Dyrk1a, by interfering with the calcineurin signalling pathway that allows tumours to grow their own blood supply.

The findings offer a mechanism for the reduced frequency of solid cancers in Down’s syndrome, and highlight the calcineurin pathway as a potential avenue for therapeutic intervention in cancer.

Article DOI: 10.1038/nature08062