Congenital bilateral absence of the vas deferens （CBAVD） is a frequent cause of obstructive azoospermia, and mutations of the cystic fibrosis transmembrane conductance regulator （CFTR） gene have also been frequent...Congenital bilateral absence of the vas deferens （CBAVD） is a frequent cause of obstructive azoospermia, and mutations of the cystic fibrosis transmembrane conductance regulator （CFTR） gene have also been frequently identified in patients with CBAVD. However, the distribution of the CFTR polymorphisms M470V, poly-T, TG-repeats and F508del mutation in the Chinese CBAVD population with presumed low cystic fibrosis （CF） frequency remains to be evaluated. Samples obtained from 109 Chinese infertile males with CBAVD and 104 normal controls were analyzed for the presence of CFTR （TG）m（T）n, M470V and F508del by PCR amplification followed by direct sequencing. Our study showed that the F5OSdel mutation was not found in our patients. The 5T mutation was present with high frequency in Chinese CBAVD patients and IVS8-5T linked to either 12 or 13 TG repeats was highly prevalent among CBAVD patients （97.22% of 72 cases and 96.91% of 97 alleles with IVS8-5T）. Moreover, a statistically significant relationship between TG 12-5T-V470 haplotype and CBAVD was detected. This study indicated that the CFTR polymorphisms poly-T, TG-repeats and M470V might affect the process of CBAVD in the Chinese population.展开更多
AIM: To investigate the three important cystic fibrosis transmembrane conductance regulator (CFTR) haplotypes poly-T, TG-repeats and the M470V polymorphisms in the Chinese population, and to compare their distribution...AIM: To investigate the three important cystic fibrosis transmembrane conductance regulator (CFTR) haplotypes poly-T, TG-repeats and the M470V polymorphisms in the Chinese population, and to compare their distribution with that in Caucasians and other Asian populations. METHODS: Genomic DNA was extracted from blood leukocytes. 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. 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: 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. Thus, they may be able to explain the low incidence of CF and CF-like diseases in Asians.展开更多
文摘Congenital bilateral absence of the vas deferens （CBAVD） is a frequent cause of obstructive azoospermia, and mutations of the cystic fibrosis transmembrane conductance regulator （CFTR） gene have also been frequently identified in patients with CBAVD. However, the distribution of the CFTR polymorphisms M470V, poly-T, TG-repeats and F508del mutation in the Chinese CBAVD population with presumed low cystic fibrosis （CF） frequency remains to be evaluated. Samples obtained from 109 Chinese infertile males with CBAVD and 104 normal controls were analyzed for the presence of CFTR （TG）m（T）n, M470V and F508del by PCR amplification followed by direct sequencing. Our study showed that the F5OSdel mutation was not found in our patients. The 5T mutation was present with high frequency in Chinese CBAVD patients and IVS8-5T linked to either 12 or 13 TG repeats was highly prevalent among CBAVD patients （97.22% of 72 cases and 96.91% of 97 alleles with IVS8-5T）. Moreover, a statistically significant relationship between TG 12-5T-V470 haplotype and CBAVD was detected. This study indicated that the CFTR polymorphisms poly-T, TG-repeats and M470V might affect the process of CBAVD in the Chinese population.
基金Supported by The Key Talent of Traditional Chinese Medicine, Foundation from the Government of Jiangsu Province, No. [2007] 158
文摘AIM: To investigate the three important cystic fibrosis transmembrane conductance regulator (CFTR) haplotypes poly-T, TG-repeats and the M470V polymorphisms in the Chinese population, and to compare their distribution with that in Caucasians and other Asian populations. METHODS: Genomic DNA was extracted from blood leukocytes. 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. 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: 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. Thus, they may be able to explain the low incidence of CF and CF-like diseases in Asians.
