Letter : Genetic clues to cancer

Sir: With reference to your article "Islanders may hold gene clue to cancer"(27 September), I am, in fact, the doctor at St Mark's Hospital to whom you refer.

May I correct some minor mistakes that have crept into the article. I work for the Imperial Cancer Research Fund and not the International Cancer Research Fund. Also, I am funded by Imperial Cancer and not by Marie Curie Cancer Research.

I am not aware of any evidence to support your statement that HNPCC-related cancers are increasing with every generation. In fact, these genes have only just been identified and we have no precise data on their frequency.

You say that one-sixth of all cancers in Finland can be traced back to a single village. However, the Finnish data actually shows that about one-sixth of their HNPCC families all carry the same distinctive HNPCC gene mutation. Moreover, that this mutation arose as a single event that can be traced back to a founder in a Finnish village in the mid-1600s.

Dr IAN M FRAYLING

St Mark's Hospital

Harrow, London