Association of XRCC1 gene polymorphisms with idiopathic azoospermia in a Chinese population

Aim： To assess the possible role of genetic polymorphisms in DNA repair gene XRCC 1 （X-ray repair cross-comple- menting group l） during spermatogenesis by investigating the associations of one promoter polymorphism （T-77C） and two exonic polymorphisms （Argl94Trp and Arg399Gln） in XRCC1 gene with risk of idiopathic azoospermia in a Chinese population. Methods： The genotype and allele frequencies of three observed polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism based on a Chinese population consisting of 171 idiopathic azoospermia subjects and 247 normal-spermatogenesis controls. Results： In our study, all the observed genotype frequencies were in agreement with Hardy-Weinberg equilibrium. The 399A （GA＋AA） allele frequency for idiopathic azoospermia subjects and controls was 0.216 and 0.269, respectively. Compared with GG genotype, the AA genotype of Arg399Gln showed a significant association with a decreased risk of idiopathic azoospermia （odds ratio = 0.315; 95% confidence interval = 0.12-0.86）. However, no significant differences were found between the cases and controls for T-77C and Arg194Trp polymorphisms. The major haplotypes of XRCC1 gene were TCG, TrG and TCA, whereas no haplotypes appeared to be significantly associated with idiopathic azoospermia based on the cutoff of P 〈 0.05. Conclusion： In a selected Chinese population, AA genotype of Arg399Gln appears to contribute to a decreased risk of idiopathic azoospermia, while we have not any evidence of involvement of XRCC1 T-77C and Arg194Trp polymorphisms in idiopathic azoospermia. （Asian J Androl 2007 Nov; 9： 843-848）

Testicular volume is a noninvasive predictor of sperm retrieval failure in idiopathic nonobstructive azoospermia

We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia(iNOA).We studied 193 patients with nonobstructive azoospermia who underwent microsurgical testicular sperm extraction.The Chi-square test and Mann–Whitney U tests for clinical parameters and seminiferous tubule distribution were used for between-group comparisons.A logistic regression analysis was conducted to identify predictors of retrieval failure.Area under the receiver operating characteristic curve for each variable was evaluated,and the net clinical benefit was calculated using a clinical decision curve.Patients with iNOA had a lower sperm retrieval rate than those with known causes.Moreover,testicular volume was an independent factor affecting sperm extraction outcomes(odds ratio=0.79,P<0.05).The testicular volume cut-off value was 6.5 ml(area under the curve:0.694).The patients with iNOA were categorized into two groups on the basis of the distribution of seminiferous tubules observed.The sperm retrieval rate and testicular volume were significantly different between the groups with a uniform or heterogeneous tubule distribution.There was also a significant association between a uniform tubule distribution and testicular volume.In conclusion,a testicular volume of more than 6.5 ml effectively predicts microsurgical testicular sperm extraction failure due to a uniform tubule distribution in patients with iNOA.