Analysis Of Common CFTR Polymorphisms Poly-T, TG-repeats And M470V In A Healthy Chinese Population Of Jiangsu Province

Objective:To investigate the three important cystic fibrosis transmembrane conductance regulator(CFTR)haplotypes poly-T,TG-repeats and the M470V polymorphisms in the Chinese population of jiangsu province,and to compare their distribution with that in Caucasians and other Asian populations.Methods:Genomic DNA was extracted from blood leukocytes by DNA Blood Mint Kit. Exons 9 and 10 of the CFTR gene were obtained through polymerase chain reaction(PCR).Exon 9 DNA sequences were directly detected by an automated sequencer and poly-T and TG-repeats were identified by direct sequence analysis.Pure exon 10 PCR-amplified products were digested by HphI restriction enzyme and the M470V mutation was detected by the AGE photos of digestion products.Results:T7 was the most common(93.6%)haplotype and the(TG)11 frequency of 57.2%and(TG)12 frequency of 40.9%were dominant haplotypes in the junction of intron 8(IVS-8)and exon 9.The frequency of T5 was 3.8%and all T5 allele tracts(10 alleles)were joined with(TG)12.Four new alleles of T6 (1.5%)were found in three healthy individuals.In exon 10,the V allele (56.1%)was slightly more frequent than the M allele(43.9%),and the M/V (45.5%)was the dominant genotype in these individuals,following were the genotypes VV(33.3%)and MM(21.21%).The three major haplotypes T7-(TG)11-V470,T7-(TG)12-M470 and T7-TG11-M470 were related to nearly 86.0%of the population.Conclusion:1.The polymorphisms of poly-T,TG-repeats,and M470V distribution were similar to those in other East Asians,but they had marked differences in frequency from those single haplotype polymorphisms or linkage haplotypes in Caucasians.The frequency of the most common atypical CF mutation T5 was lower than those of Caucasians,The major haplotypes were T7-(TG)11-V470 and T7-(TG)12-M470,similar to Japanese and Vietnamese, However,in Caucasians,two main haplotypes,T7-(TG)11-V470 and T7-(TG)10-M470 are predominant,Thus,they may be able to explain the low incidence of CF and CF-like diseases in Asians.2.This study investigated three important CFTR haplotypes,poly-T,TG repeats and M470V polymorphisms in 132 healthy Chinese population.It provides important genetics data for CFTR gene polymorphisms background and the study of CF and CF-like diseases in the Chinese population.It also provides normal control group data for the correlation of CFTR gene polymorphisms and Tan Zheng,as well as to abundant the theory of Chinese medical science Tan Zheng and to establish the empirical method foundation for next study.