Estimated analytic validity of HFE C282Y mutation testing in population screening: The potential value of confirmatory testing

Purpose: The purpose of this study was to estimate analytic sensitivity and specificity of HFE testing for C282Y homozygosity in the hypothetical setting of population screening for hemochromatosis. Methods: We analyzed published results of the Molecular Genetics Survey performed by the American College of Medical Genetics/ College of American Pathologists between 1998 and 2002, taking into account its educational nature. Results: Analytic sensitivity for C282Y homozygosity is 98.4% (95% Cl 95.9%-99.5%). The analytic specificity is 99.8% (99.4%-99.9%). At a frequency of 40 per 10,000 for the homozygous genotype, the analytic positive predictive value is 66%. Conclusion: HFE testing for C282Y homozygosity is highly reliable. Homozygosity is uncommon in population screening, however, and confirmatory testing should be considered.