Hereditary haemochromatosis

Abstract

Hereditary haemochromatosis syndromes are inherited disorders whereby inappropriate absorption of iron by the small intestine leads to iron deposition in the viscera, endocrine organs, and other sites, causing structural injury and impaired function. The most common form is classical adult (HFE-related) haemochromatosis, but other forms are recognized. Extended genetic platforms are increasingly used for specific diagnosis and noninvasive methods are increasingly used to evaluate hepatic damage. The mainstay of treatment is venesection although iron chelation therapy is an emerging oral alternative. Unravelling the molecular genetics of haemochromatosis is underpinning promising new therapies for disorders of iron homeostasis. Classical adult (HFE-related) haemochromatosis: aetiology and pathogenesis—inherited as a recessive trait and due to mutations in the major histocompatibility complex class I-related HFE gene that appear to reduce liver production of hepcidin. The principal mutant allele of HFE, designated C282Y, is carried by approximately 1 in 10 individuals of European ancestry, hence around 1 in 200 are homozygotes, usually with biochemical abnormalities of iron storage that may lead to full-blown clinical haemochromatosis. Clinical features—expression of disease may range from slight abnormalities of blood parameters that reflect iron metabolism to the established clinical syndrome of cutaneous pigmentation, cardiomyopathy, endocrine failure (especially diabetes mellitus and hypogonadism), arthritis, and pigment cirrhosis. Diagnosis—usually established by demonstrating abnormalities of iron metabolism. Molecular analysis of the HFE gene, in particular for homozygosity for the C282Y allele, is confirmatory. Management and prognosis—this is directed to the removal of iron by phlebotomy until the serum ferritin concentration is reduced to within the low normal range, after which the frequency of phlebotomy is reduced. Family members—first-degree relatives should be offered screening.