The hereditary hemochromatosis associated with HFE gene (Hemochromatosis type I, HFE-HCC) is an inherited autosomal recessive disorder characterized by an increased absorption of iron at the level of the gastrointestinal mucosa, with consequent accumulation of the same at the level of the liver, the skin, pancreas, heart, joints and testes. It is the most common autosomal recessive disease in Caucasians. Abdominal pain, weakness, lethargy and weight loss are the earliest symptoms that, in the absence of appropriate therapy, may develop in men between 40 and 60 years, and in women after menopause. Outcomes dreaded disease are made from cirrhosis and liver fibrosis, together with endocrine dysfunction.
The HFE gene is located on chromosome 6 (6p21.3) and encodes a protein of 348 aa (precursor) very similar to proteins of HLA class I. The mature protein is expressed on the cell surface as a heterodimer with the b2-microglobulin. The HFE protein consists of two extracellular domains a1 and a2 that interact with the transferrin receptor, from a domain a3, immunoglobulin-like, which binds to the b2-microglobulin, a transmembrane domain, plus a cytoplasmic one. The HFE protein, binding to the transferrin receptor 1, it would set in a negative way, by reducing the release of iron in the cell cytoplasm and then the uptake of iron. At least 28 distinct mutations in the HFE gene have been reported, but only two mutations, that are Cys282Tyr (C282Y, 845 GA>) and (H63D, 187C>G) account for the majority of alleles that can cause disease.
A third mutation in HFE is a substitution A193T in exon 2 which involves an amino acid change S65C. It has been shown to be generally benign, although a genotype C282Y/S65C may confer an increased risk of development of hemochromatosis, contributing to a mild phenotype of the disease. Approximately 60-90% of individuals of European origin with HFE-HHC are homozygous for the C282Y mutation, 3-8% is compound heterozygous for C282Y and H63D mutations and 1% are homozygous for H63D. Approximately 5% of subjects with a clinical picture suggestive of hemochromatosis are only heterozygous for the C282Y mutation. They probably have another rare mutation in HFE or mutations in other genes responsible for iron accumulation. The incidence of homozygous for C282Y in the European population is between 1:200 and 1:400, and while low in African Americans and even more among Asians.
The test is available in sizes from 24, 48 or 72 reactions.
Screening test for: Hereditary Hemochromatosis