Linkage analysis of 6p21 polymorphic markers and the hereditary hemochromatosis: localization of the gene centromeric to HLA-F.

Hereditary Hemochromatosis (HFE) is one of the most common inherited disorders with an estimated frequency of homozygous patients of 0.002-0.0045. The disease is characterized by increased intestinal iron absorption and progressive iron overload. Affected subjects show clinical symptoms of parenchymal organ damage after the third-fourth decade of life and have a 200 fold increased risk of developing hepatocellular carcinoma. Early diagnosis and treatment prevent complications and may normalize life expectancy of patients. The biochemical and genetic defects leading to progressive iron accumulation are still unknown, but the HFE gene is tightly linked to HLA complex on the short arm of chromosome 6. Utilizing HLA serotypes and the study of several polymorphic markers of 6p21, a linkage analysis of the disease locus was performed in a series of Italian hemochromatosis families. The data obtained by linkage analysis and the study of a family with a double recombinant allowed us to better define the HFE gene location with respect to HLA-class I A and F loci.