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.[1][2] 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.[1][3]
| Juvenile hemochromatosis | |
|---|---|
| Other names | Hemochromatosis type 2 |
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.[3] Depending on which of these genes is affected, the disease can be further subdivided into types 2A and 2B.[2]
The most common symptoms of juvenile hemochromatosis are as follows:[2][3][4]
Other common complications include:
Less common symptoms and complications include:
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.[2][3]
Type 2A is the most common form, accounting for roughly 9 out of every 10 cases of the disease.[2]
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.[citation needed]
Juvenile hemochromatosis shares signs and symptoms with many other conditions including:[2][3][4]
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. Elevated serum ferritin, an indicator of blood iron levels, and transferrin saturation, which is involved with absorption of iron from the gut, are very common.[2][3]
In patients suspected to have juvenile hemochromatosis, the diagnosis can be confirmed through genetic testing for specific genes:[4]
MRI may be utilized in order to assess the extent to which iron has been deposited in certain tissues and organs, however does not have significant weight in the diagnosis of the condition.[4]
Liver biopsy, or removal of a small piece of liver tissue for analysis, can be done to assess the extent of iron overload in the liver, however is considered not to have a significant weight in the diagnosis of the condition.[4]
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.[2][3][4] 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, 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.[4] After these levels are reached, phlebotomy will be continued, but less often than once weekly, perhaps every few months.[3]
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.[2][3][4] Examples of chelators specifically for iron include deferoxamine and deferasirox.
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.[1][3][4]
If the disease is advanced enough, further treatments can be aimed at the complications of the disease, depending on which are present:[2][4]
The incidence of juvenile hemochromatosis in the general population remains unknown at this time, however it is very rare. It more commonly occurs in those of European descent, becoming apparent during the first to third decades of life, and affects males and females at similar rates.[2][3][4]