Examining the clinical use of hemochromatosis genetic testing

Hereditary hemochromatosis leads to an increased lifetime risk for end-organ damage due to excess iron deposition. Guidelines recommend that genetic testing be performed in patients with clinical suspicion of iron overload accompanied by elevated serum ferritin and transferrin saturation levels.

To evaluate guideline adherence and the clinical and economic impact of HFE genetic testing.

The electronic charts of patients submitted for HFE testing in 2012 were reviewed for genetic testing results, biochemical markers of iron overload and clinical history of phlebotomy.

A total of 664 samples were sent for testing, with clinical, biochemical and phlebotomy data available for 160 patients. A positive C282Y homozygote or C282Y⁄H63D compound heterozygote test result was observed in 18% of patients. Patients with an at-risk HFE genotype had significantly higher iron saturation, serum iron and hemoglobin (P<0.001), without higher ferritin or liver enzyme levels. Fifty percent of patients referred for testing did not have biochemical evidence of iron overload (transferrin saturation >45% and ferritin level >300 μg⁄L). Patients were four times more likely to undergo phlebotomy if they were gene test positive (RR 4.29 [95% CI 2.35 to 7.83]; P<0.00001).

One-half of patients referred for testing did not exhibit biochemical evidence of iron overload. Many patients with biochemical evidence of iron overload, but with negative genetic test results, did not undergo phlebotomy. A requisition to determine clinical indication for testing may reduce the use of the HFE genetic test. Finally, improvement of current genetic test characteristics would improve rationale for the test.

A significant proportion of hemochromatosis genetic testing does not adhere to current guidelines and would not alter patient management.