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. Without functional hemojuvelin, hepcidin levels are reduced, and the amount of iron absorbed into the blood during digestion is unable to be halted. Type 2B is caused by inheriting two mutated alleles, one from each parent, for the HAMP gene, which encodes the protein hepcidin. Hepcidin is responsible for regulating absorption of iron from the small intestine to the blood during the digestion of food, such to prevent blood iron levels from becoming too high. A lack of functional hepcidin prevents the body from stopping iron absorption when it has already reached adequate levels.Type 2A is the most common form, accounting for roughly 9 out of every 10 cases of the disease. Diagnosis
An individual may be suspected to have this condition based on their medical history, physical exam findings, and blood tests, and confirmation of the diagnosis can be made with further testing, often with use of gene panels. Differential Diagnosis
Juvenile hemochromatosis shares signs and symptoms with many other conditions including:
Other types of hereditary hemochromatosis
Atransferrinemia
Aceruloplasminemia
African iron overload
Neonatal hemochromatosis
Transfusional iron overload and other forms of secondary hemochromatosis
Porphyria cutanea tarda

Blood Testing
The presence of hemochromatosis may be discovered incidentally on blood testing, or a diagnosis suspected based on symptoms may be supported or ruled out by blood testing.
Treatment
Treatment for juvenile hemochromatosis is similar to that for other forms of hemochromatosis and iron overload, and focuses on reducing the amount of iron in the body in order to prevent complications of iron overload. However, if the disease is not discovered early enough, or if progress is not well controlled, further treatments may be aimed at the symptoms of organ damage which may develop. Phlebotomy
Phlebotomy, the removal of blood from the body, is the main treatment for juvenile hemochromatosis. One unit of blood, the amount typically given during blood donation, is typically removed per session, and it is generally recommended that this be done once weekly until acceptable levels of iron are in the blood, which may take years. After these levels are reached, phlebotomy will be continued, but less often than once weekly, perhaps every few months. Chelation Therapy
In the event that phlebotomy is not an appropriate option or is not enough on its own to reduce iron levels, chelation medications, those that bind and remove certain metals from the blood, may be utilized. Examples of chelators specifically for iron include deferoxamine and deferasirox. Dietary Modification
It is recommended that those with juvenile hemochromatosis refrain from eating iron supplements, vitamin C supplements, and uncooked/undercooked seafood and shellfish, and reduce or eliminate consumption of alcoholic beverages and red meat. Additional Treatments
If the disease is advanced enough, further treatments can be aimed at the complications of the disease, depending on which are present:
Diabetes may be treated with oral medications and/or insulin as indicated.