Prevalence of the C282Y mutation in Brittany: Penetrance of genetic hemochromatosis?

Hemochromatosis (GH) is an inborn error of iron metabolism, characterized b y progressive iron loading that, if untreated, causes high morbidity and de ath. The gene responsible for the disease (HFE), located 4.5 megabases telo meric to the HLA-A locus, encodes a protein homologous to class I MHC molec ules. A main mutation, C282Y, has been identified within the gene. Although hemochromatosis is considered as the most frequent inherited disease in th e populations of Northern European origin, its prevalence in Brittany had n ot been evaluated yet. In this issue we report the C282Y mutation frequency in a cohort of 1000 newborns from maternity hospitals of the four breton d epartements. The homozygote frequency was 5 parts per thousand and heterozy gote frequency was 12%; such high frequencies raise the question of the pen etrance of the disease and the relevance of systematic genotypic screening for hemochromatosis.