Prevalence of the Cys282Tyr and His63Asp mutation in flemish patients withhereditary hemochromatosis

Recently Feder et al. have identified the gene responsible for hereditary h emochromatosis; it is located 3 Mbp telomeric of the MHC region on chromoso me 6p and is called the HFE gene, The majority of the patients with hemochr omatosis harbour the same missense mutation, Cys282Tyr. A second missense m utation (His63Asp) of which the significance is Less clear, has also been d escribed. To our knowledge the percentage of these two missense mutations i n Flemish hemochromatosis patients is not known. Materials and methods: Forty nine (49) unrelated patients with the clinical diagnosis of hemochromatosis were screened for the two missense mutations. The missense mutations were diagnosed with a PCR technique. Results: Of the 49 patients, 46 patients were homozygous for the Cp282Tyr m utation (94%), 2 were heterozygous (4%) and 1 carried two normal alleles (2 %). Of the 3 patients not homozygous for the Cp282Tyr mutation, 3 were hete rozygous for the His63Asp mutation (2 patients were 'compound heterozygotes '). Discussion: The percentage of homozygotes (Cys282Tyr) in a Flemish hemochro matotic population is comparable with the figures published in the Literatu re. The second missense mutation (His63Asp) could be of importance in assoc iation with the Cys282Tyr missense mutation.