Human alpha-L-iduronidase (IDUA) gene: correlation of polymorphic DNA haplotype and IDUA activity in Chinese population

Lee-Chen, G.J.; Wang, C.K.; Huang, S.F.; Day, K.R.

Proceedings of the National Science Council Republic of China. Part B Life Sciences 22(1): 31-38

1998


ISSN/ISBN: 0255-6596
PMID: 9536518
Document Number: 1020
The correlation of polymorphic DNA haplotype of the α-L-iduronidase (IDUA) gene and IDUA activity in Chinese subjects was investigated. Genomic DNA extracted from 85 randomly sampled normal individuals was used to amplify fragments containing the polymorphic change site A8, Q33H (exon 1), R105Q (exon 3), A361T (exon 8), or V454I (exon 9). The PCR amplified products were analyzed by means of restriction fragment length polymorphism (RFLP) or allele specific oligonucleotide (ASO) hybridization. Leukocytes were isolated from the above 85 samples, and their IDUA activities were determined. A wide range of IDUA activity (50-300 nmol/h/mg cell protein) with an average of 156 nmol/h/mg cell protein was observed. When the allele frequency was compared between individuals with IDUA activity below 90% or above 110% of the average, a bias toward the common allele "1" of Q33H (G1n33) was detected in individuals with higher IDUA activity. Conversely, the polymorphic allele "2" of R105Q (Glitios), A361T (Thr361), and V454I (I1e454) was found in the higher IDUA activity group. Linkage disequilibrium analysis of the haplotype data revealed strong nonrandom association among the polymorphic alleles of R105Q, A361T, and V454I. Of the haplotypes constructed by Q33H, R105Q, A361T, and V454I, a positive correlation between haplotype 1,2,2,2 (G1n33, Glnio5, Thr361, I1e454) and IDUA activity was observed. The IDUA activity was found to increase with Glni05, Thr361, or I1e454 polymorphic changes by mutagenesis and expression of IDUA cDNA in COS-7 cells. By combining the positive effect of Glni05, Thr361, and IIe454 in one cDNA construct, it may be possible to produce a high activity IDUA protein for MPS I enzyme replacement therapy.

Document emailed within 1 workday
Secure & encrypted payments

Human alpha-L-iduronidase (IDUA) gene: correlation of polymorphic DNA haplotype and IDUA activity in Chinese population