The molecular basis of hereditary fructose intolerance in Italian children.

We investigated the molecular defects of the aldolase B gene in five unrelated patients affected by hereditary fructose intolerance. The techniques used were DNA amplification, direct sequencing and allele-specific oligonucleotide (ASO) hybridization. The most frequent substitutions found in the hereditary fructose intolerance alleles analysed were the A174D and the A149P mutations, which account for 50% and 30% of the alleles, respectively. In two unrelated families, we found a rare mutation, the MD delta 4 previously described only in one British family, which may be an important cause of the disease in Italy.