9 June 2006
The Human Fertilisation and Embryology Authority (HFEA) has issued draft recommendations on widening the number of conditions for which PGD may be used, for discussion at a public meeting of the authority in Belfast tomorrow (10th May). This follows on from a public consultation on widening the scope of PGD launched in November 2005.
PGD or pre-implantation genetic diagnosis in the UK requires a license from the HFEA. All licences granted so far have been for fully (or almost fully) penetrant diseases such as cystic fibrosis and Huntington's disease. However the HFEA recently carried out a consultation on what its policy should be for late onset conditions that are incompletely penetrant and are also (at least to some extent) treatable or preventable, such as familial forms of breast/ovarian and colorectal cancer.
The BRCA1 and BRCA2 mutations are associated with a 40-80% lifetime risk of breast cancer and a 10-50% risk of ovarian cancer, whilst the MMR gene mutations linked with HNPCC carry a lifetime risk of up to 80% for colon cancer in men and 30-60% for endometrial cancer in women. The precise probabilites of a mutation carrier developing disease (penetrance) are difficult to calculate precisely and different studies have produced variable results. PGD has already been approved for two inherited types of cancer, familial adematous polyposis (FAP) colon cancer, and retinoblastoma; these conditions affect children and young adults, although effective treatments are available.
The HFEA's ethics and law committee reportedly recommends it would be appropriate, in principle, to extend the use PGD for cancer genes "because the features of the conditions are not incompatible with them being regarded as serious genetic conditions" (see BBC news report). Former British Fertility Society chair Dr Richard Kennedy commented: