Semi-automated, reverse-hybridization detection of multiple mutations causing hereditary fructose intolerance

Hereditary fructose intolerance (HFI) is a potentially fatal nutritional disease that is caused by mutations in the liver isoenzyme of fructoaldolase (aldolase B). Our aim was to evaluate a diagnostic assay capable of simultaneously analyzing three-point mutations and a small deletion in the aldolase B (ALDOB) gene. The test under investigation is based on multiplex DNA amplification and hybridization to membrane strips presenting a parallel array of allele-specific oligonucleotide probes. We used the novel reverse-hybridization (RH) protocol to analyze 54 individuals previously genotyped by direct sequencing. RH genotyping for ALDOB mutations Delta4E4, A149P, A174D, and N334K was in complete concordance with results obtained by DNA sequencing. The procedure is rapid (<6h) and may be automated to a large extent. The RH assay tested in this study represents an accurate and robust screening tool to identify common ALDOB mutations.