HUMAN ALPHA-L-IDURONIDASE (IDUA) GENE - APPARENT RECOMBINATION IN INTRON-2 BY HAPLOTYPE ANALYSIS IN A TAIWANESE POPULATION

The polymorphic DNA haplotype of the alpha-L-iduronidase (IDUA) gene i n a Taiwanese population was investigated. Genomic DNA extracted from 85 volunteers was used to amplify fragments containing the polymorphic sites A8, A20 and Q33H from exon 1 and a variable number of tandem re peats (VNTR) region in intron 2. Additionally, sites R105Q and L118 in exon 3, A314 from exon 7, A361T and T388 from exon 8, T410 and V454I from exon 9, and R489 from exon 10 were amplified. The polymerase chai n reaction-amplified products were analyzed by restriction fragment le ngth polymorphism (RFLP) analysis, allele specific oligonucleotide (AS O) hybridization, or gel electrophoresis. Of the examined polymorphism s, the intron 2 VNTR was not in Hardy-Weinberg equilibrium. Conversely , all 11 single base change polymorphisms were in Hardy-Weinberg equil ibrium. Linkage disequilibrium analysis of the haplotype data revealed strong nonrandom association bet tween A8 and A20 in exon 1 as well a s among R105Q. A314, A361T, T388, T410, V454I, and R489 in exons 3 to 10. In contrast, little linkage disequilibrium between two clusters of linked polymorphisms on either side of the VNTR was observed. The res ults suggest apparent recombination in intron 2 of the IDUA gene, with little or no recombination in exon 1 or exons 3 to 10.