Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 470

Mutations in the HFE gene are the cause of most cases of hemochromatosis. Homozygous C282Y mutation or C282Y and H63D combined mutation account for most cases. However, most patients with these mutations do not develop iron overload, as other factors play a role, such as iron consumed and lost and alcohol use. Patients with the genetic defect absorb about 3 mg of iron daily compared to 1 mg in normal people on a typical Western diet. People become symptomatic when total body iron stores are greater than 20 g, usually after age 40 in men and 60 in women. The mutation occurs in 7% of the Caucasian population, for a prevalence of 0.3–0.7% in this population, and much less frequently in other ethnic groups.²⁶

Patients present with multiple manifestations reflecting iron deposition in multiple organs. Symptoms include fatigue, hepatomegaly, increased transaminase, cirrhosis, hepatocellular cancer, diabetes, cardiomyopathy, hypopituitarism, and arthropathy. There should be a low threshold for testing for hemochromatosis in anyone with suggestive manifestations, as screening tests are easily obtained and treatment will prevent progression. Screening tests are iron, iron‐binding/transferrin, and ferritin. An iron saturation of greater than 45% or ferritin greater than 200 should prompt further testing with a genotype, liver biopsy with iron determination, or an MRI, which can accurately detect iron overload.

Treatment consists of determining the stage by estimating fibrosis with liver biopsy and other means and then phlebotomy weekly or biweekly until the ferritin is less than 50.²⁷ If caught and treated in time, hepatic and other manifestations of the disease will not occur. This disease often has its first manifestation after age 65, particularly in females.