A 45-year-old male with a confirmed diagnosis of hemochromatosis tests negative for the 2 most common mutations in the HFE gene known to cause this disease. The patient and several family members, including an affected brother and uncle, are tested for 5 single nucleotide polymorphisms (SNPs) closely linked to the HFE gene on chromosome 6. No linkage is found in this family to any of these markers. What is the most likely explanation for these results?

1. A)Incomplete penetrance
2. B)Heteroplasmy
3. C)Locus heterogeneityGABARITO
4. D)A rare HFE allele
5. E)Recombination between the SNPs and the HFE gene