Molecular analysis of aldolase B genes in hereditary fructose intolerance.

The molecular basis of hereditary fructose intolerance (HFI) was studied in 50 subjects (41 pedigrees, 82 apparently independent mutant alleles of aldolase B) by direct analysis of aldolase B genes amplified by means of the polymerase chain reaction. The mutation A149P (ala 149----pro) was found in 67% of alleles but was significantly more common in patients from northern than from southern Europe. Two other point mutations of aldolase B were identified. A174D (C----A; ala 174----asp) was found in subjects from Italy, Switzerland, and Yugoslavia (overall frequency 16%) but not in those from the United Kingdom, France, or the United States. L288 delta C carried a single base-pair deletion causing frameshift at codon 288 and was restricted to Sicilian subjects. By testing for these mutations in amplified DNA with a limited panel of allele-specific oligonucleotides, more than 95% of HFI patients will be susceptible to genetic diagnosis.