Retrospective Evaluation of Patients Referred for Hemochromatosis Genetic Testing

Background: The common genetic test for hemochromatosis involves the genotyping of two polymorphisms in the HFE gene (C282Y and H63D). Current guidelines suggest testing of patients with ferritin greater than 300 µg/L and transferrin saturation greater than 45%. Testing of first degree relatives of confirmed HFE positive cases is also endorsed. However, the current test has poor sensitivity and specificity for iron overload causing end organ damage. We sought to evaluate biochemical parameters of patients referred for HFEtesting and identify those who received phlebotomy.

Methods: After receiving ethics approval, electronic charts of patients referred to Hamilton Health Sciences, Hamilton, Ontario, Canada for HFE genetic testing between January 1, 2012 and December 31, 2012 were reviewed.

Results: HFE genetic testing in 642 patients yielded 100 (15.6%) positive C282Y homozygote or C282Y/H63D compound heterozygote results. In patients with biochemical markers of iron overload available (n=160), patients with a risk HFE genotype had significantly higher iron saturation, serum iron, and hemoglobin (P<0.001), but did not have higher ferritin or liver enzymes. Only fifty percent of patients referred had biochemical evidence of iron overload (transferrin saturation [TS] > 45% and ferritin > 300). Of patients who required phlebotomy, only 27 of 40 (67.5%) were HFEpositive.

Conclusion: Many factors affect the decision to phlebotomize a patient with suspected iron overload. However, it appears that most of the current HFE genetic testing being performed did not alter patient management.