Fluorescent multicolor multiplex homogeneous assay for the simultaneous analysis of the two most common hemochromatosis mutations.

We report the development of a qualitative fluorescent multiplex homogeneous assay designed for the detection of the two most common hemochromatosis mutations using dual-labeled fluorescent probes. The assay is able to detect four allelic variants in a single closed tube using a single thermocycling protocol. The procedure combines the great sensitivity of the polymerase chain reaction, the specificity provided by allele-specific oligonucleotide hybridization using the 5(') nuclease assay format, and the higher throughput of a multicolor fluorescence detection procedure. Genomic DNA was prepared from whole blood specimens using standard procedures. Following DNA sample preparation, two regions of the hemochromatosis gene (HFE) including the H63D and C282Y mutations were coamplified and detected in real-time by four different fluorescently labeled allele-specific oligonucleotide probes. Assay specificity was demonstrated by a blind methods comparison study that included 37 DNA samples from individuals with a known HFE genotype. Results from the study showed that the multicolor multiplex HFE assay unambiguously classified all possible genotypes for the HFE gene C282Y and H63D mutations(1). This technique will be useful for research and molecular diagnostic laboratories and can be easily adapted for the detection of other single nucleotide polymorphisms.