Hemochromatosis (sometimes known as “iron overload”) is a condition that causes the body to store excess iron, which leads to damage to various organs.
Hemochromatosis relates to several diseases, some are inherited (genetic) while others are acquired (secondary). Some types develop during adulthood while others are neonatal (symptoms develop during infancy).
Hereditary hemochromatosis (adult onset, or primary hemochromatosis)
Hereditary hemochromatosis is caused by a mutation to the HFE gene, located on chromosome 1.
Most patients inherit a gene mutation known as C282Y. In these cases, the patients’ intestinal tract absorbs too much iron, which builds up in organs such as the heart, liver, pancreas, joints, and more.
Another common gene mutation is called H63D. Patients with this variant usually develop milder symptoms which lead to fewer complications. In addition, the disease can be caused by a variant in any of the genes coded to iron transport proteins.
In addition to genetic disorders that cause excess iron absorption or impaired iron transport, there are other diseases that can cause excess levels of iron. For instance, hemolytic anemia is a condition in which red blood cells are broken down in an abnormal rate and iron is released into the blood stream. Thalassemia major is a disease characterized by impaired iron metabolism.
How is the disease diagnosed?
Adult-onset hemochromatosis is diagnosed through blood tests that measure iron levels, and serum transferrin saturation tests. Transferrin is a protein that carries iron in the blood. The higher the levels of transferrin, the higher the iron levels in the blood.
Symptoms include a loss of sex drive, unexplained arithritis, infertility, liver dysfunction, irregular heart rhythm, and more. People who inherit two mutated gene copies with the variant C282Y may develop severe symptoms such as liver cancer, cirrhosis of the liver, and diabetes.
Genetic testing can help detect HFE gene mutations and determine whether a person has inherited the hereditary form of this condition.
Prenatal testing is not usually offered for this disease.
Babies with neonatal hemochromatosis are born suffering from kidney failure and a significant iron excess in the liver, detectable through MRI testing. Although iron accumulation stops after birth, in most cases performing a liver transplant is unaviodable.
The neonatal type is most likely caused by placental iron transfer. However, the gene mutation that causes this condition has not yet been identified.
The disease can be diagnosed prenatally through a magnetic resonance imaging (MRI).
After having a child with neonatal hemochromatosis, women have a 100% chance of being affected by the same condition in subsequent pregnancies.