Association of USP26 haplotypes in men in Taiwan, China with severe spermatogenic defect

Aim: To complete comprehensive haplotype analysis of USP26 for both fertile and infertile men. Methods: Two hundred infertile men with severe oligospermia or non-obstructive azoospermia were subjected to sequence analysis for the entire coding sequences of the USP26 gene. Two hundred men with proven fertility were genotyped by primer extension methods. Allele/genotype frequencies, linkage disequilibrium (LD) characteristics and haplotypes of fertile men were compared with infertile men. Results: The allele frequencies of five single nucleotide polymorphisms (370-371insACA, 494T > C, 576G > A, ss6202791C > T, 1737G > A) were significantly higher in infertile patients than control subjects. The major haplotypes in infertile men were TACCGA (28% of the population), TGCCGA (15%), TACCAA (8%), TGCCAA (6%), TATCAA (5%) and CATCAA (5%). The major haplotypes for the control subjects were TACCGA (58% of the population), CACCGA (7%), CATCGA (6%) and TGCCGA (5%). Haplotypes TGCCGA, TATCAA, CATCAA, CATCGC, TACCAA and TGCCAA were over-transmitted in patients with spermatogenic defect, whereas haplotypes TACCGA, CACCGA, and CATCGA were under-transmitted in these patients. Conclusion: Some USP26 alleles and haplotypes are associated with spermatogenic defect in the Han nationality in Taiwan, China.