All of these complications, however, are much more commonly seen in persons who do not have HH, so without a family history or iron studies, HH will not be suspected. It should be noted that, thoughout most of human history, the average lifespan was not great enough to allow manifestation of HH, so the appearance of persons with complications of HH is a relatively modern phenomenon. The diagnosis of HH depends upon documenting excessive iron storage. This can be accomplished by measuring serum iron and iron binding capacity with calculation of percent saturation. The iron and the percent saturation should be high.
Serum ferritin is also a good indicator of the amount of storage iron in the body.
The most common causes of death in individuals with HH are hepatocellular carcinoma associated with cirrhosis, hepatic failure, and cardiac failure. There appears to be a subgroup of young patients who present with severe cardiac involvement and in whom outcome is poor as a result of congestive heart failure if they remain untreated. The gene for HH is located on chromosome 6. This locus is associated with the HLA A-3 antigen. Seventy percent of HH individuals have the HLA A-3 genotype, whereas it is present in only 25 percent of normal individuals.