Juvenile hemochromatosis

Juvenile hemochromatosis, also known as hemochromatosis type 2, is a rare form of hereditary hemochromatosis, which emerges in young individuals, typically between 15 and 30 years of age, but occasionally later. It is characterized by an inability to control how much iron is absorbed by the body, in turn leading to iron overload, where excess iron accumulates in many areas of the body and causes damage to the places it accumulates. It is a genetic disorder that can be caused by mutations in either the HJV (also called HFE2) or HAMP genes, and is inherited in an autosomal recessive fashion. Depending on which of these genes is affected, the disease can be further subdivided into types 2A and 2B. The most common symptoms of juvenile hemochromatosis are as follows: Weakness Lethargy Hyperpigmentation (darkening of the skin) Arthropathy (joint disease) Diabetes Heart disease (dilated cardiomyopathy). Complications of heart disease are the main cause of death in those with untreated hemochromatosis. Hypogonadism (reduced activity of the genitals), which may result in decreased libido and infertility Amenorrhea in females Erectile dysfunction in males Loss of appetite Increased risk of infection by certain bacteria including V. vulnificus. Other common complications include: Congenital hepatic fibrosis Less common symptoms and complications include: Osteoporosis Hepatomegaly (liver enlargement) Liver cirrhosis Cardiac arrhythmias Hypothyroidism Adrenocortical insufficiency Juvenile hemochromatosis can be caused by inheriting two mutated copies (alleles), one from each parent, of the genes for the proteins hemojuvelin (HFE2/HJV) or hepcidin (HAMP), and the disease can be subdivided into hemochromatosis types 2A and 2B according to which gene/protein is affected. Type 2A is caused by inheriting two mutated alleles, one from each parent, for the HJV (aka HFE2) gene, which encodes the protein hemojuvelin. Hemojuvelin is responsible for the maintaining correct levels of the protein hepcidin, which regulates iron absorption in the blood.