Sorted By Test Name - Mayo Medical Laboratories

HHEMO
81508
States are homozygous for C282Y and 10% are heterozygous carriers, confirming that HH is the most
common, single-gene inherited disorder in Caucasians. The initial description of patients with HH was
"bronze diabetes" in association with cirrhosis. Currently, most persons diagnosed with HH are
asymptomatic. Of those with symptoms, fatigue, arthritis, and impotence are most common. Recent large,
population-based screening studies have concluded that most individuals homozygous for C282Y do not
develop clinically important disease manifestations. The true penetrance in C282Y homozygotes is
unknown. The diagnosis of HH is based on a combination of clinical, laboratory, and pathological criteria.
The best initial test for HH is a fasting, morning transferrin saturation (% saturation). If the transferrin
saturation is >45%, it should be repeated along with a serum ferritin. In adults, when both the serum
transferrin saturation and ferritin are elevated, the HFE gene test should be performed. Prior to HFE gene
testing, a qualified professional should discuss the risks, benefits, and alternatives of genetic testing.
Approximately 85% of US patients with HH are homozygous for C282Y. Absence of the C282Y and
H63D mutations does not exclude clinically significant iron overload. HFE gene testing is useful in
confirming a diagnosis of HH, screening adult blood relatives of a C282Y homozygous proband, and
helping to resolve ambiguous cases of iron overload. A liver biopsy with measurement of the hepatic iron
concentration is no longer necessary to confirm the diagnosis in C282Y homozygotes. A liver biopsy also
is not necessary in most C282Y homozygotes with serum ferritin values