Reference Interval:
C282Y Negative: The patient is negative for the HFE C282Y mutation.
H63D Negative: The patient is negative for the HFE H63D mutation.
S65C Negative: The patient is negative for the HFE S65C mutation.
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| Interpretive Data: |
Hereditary hemochromatosis is an autosomal recessive disorder of iron metabolism that varies in clinical severity. Three mutations (C282Y, H63D, and S65C) have been described in the majority of patients with hemochromatosis. Homozygosity for the C282Y mutation is responsible for up to 90% of hemochromatosis patients. Penetrance of C282Y is under debate. Current studies estimate penetrance as 80% for men and 35% for women over 40. Additional studies estimate much lower penetrance for liver disease (~1%).
The second mutation (H63D) has been described in some patients when inherited with the C282Y mutation as a compound heterozygote (C282Y/H63D). This genotype, however, has a reduced penetrance of less than 2%. C282Y/ S65C compound heterozygotes have also been reported, but the penetrance of this genotype is not known. It may contribute to a mild form of hemochromatosis. Heterozygotes for C282Y (C282Y/WT), H63D (H63D/WT), or S65C (S65C/WT) are not significantly associated with hemochromatosis, although other undetected mutations in combination with these mutations may contribute to symptoms of hemochromatosis. Homozygous H63D genotypes (H63D/H63D) rarely show symptoms of hemochromatosis, but several cases have been reported. Mutations in unidentified genes or other mutations in the HFE gene which may cause hemochromatosis are not ruled out by this analysis.
Patient DNA is assayed for the C282Y, H63D, and S65C point mutations in the hemochromatosis gene by polymerase chain reaction (PCR), and fluorescence monitoring using hybridization probes. Sensitivity and specificity for detection of this mutation are 99.9%.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
This test is performed pursuant to an agreement with BioRad Laboratories, Inc.
Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory.
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| Note: |
This test is not recommended for nonsymptomatic patients under 18 years of age.
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| CPT Code(s): |
83890 Isolation; 83900 Amplification; 83896 x4 Nucleic acid probes; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders.
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