Y chromosome b2/b3 deletions and male infertility: A comprehensive meta-analysis, trial sequential analysis and systematic review

Mutat Res Rev Mutat Res. 2016 Apr-Jun:768:78-90. doi: 10.1016/j.mrrev.2016.04.007. Epub 2016 May 4.


The correlation of Y-chromosome b2/b3 partial deletions with spermatogenic failure remains dubious. We undertook a systematic review of the literature followed by meta-analyses and trial sequential analyses in order to compare the frequency of b2/b3 deletions between oligo/azoospermic infertile and normozoospermicmen. Out of twenty-four studies reviewed for meta-analysis, twenty reported no correlation between this deletion and male infertility and two studies each reported a direct and inverse correlation. In the collective analysis, 241 out of 8892 (2.71%) oligo/azoospermic individuals and 118 out of 5842 (2.02%) normozoospermic controls had a b2/b3 deletion, suggesting a relatively higher frequency of deletions in the cases. Eventually, meta-analysis showed a significant correlation between b2/b3 deletions and the risk of spermatogenic loss/infertility (Fixed model: OR=1.313, 95% CI=1.04-1.65, p=0.02; Random model: OR=1.315, 95% CI=1.02-1.70, p=0.037). Further meta-analysis on studies grouped by ethnicity and geographic regions showed that the b2/b3 deletions are significantly associated with spermatogenic loss/infertility in Mongolians, Nigro-Caucasians, East Asians and Africans, but not in Caucasians, Europeans, South Asians and Dravidians. In summary, the Y-chromosome b2/b3 deletions increase infertility risk; however, it may be significant only in the Mongolian populations and the East Asian region.

Keywords: Male infertility; Spermatogenic failure; Y partial deletion; b2/b3 deletion.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Case-Control Studies
  • Chromosome Deletion*
  • Chromosomes, Human, Y
  • Ethnicity / genetics
  • Humans
  • Infertility, Male / genetics*
  • Male
  • Odds Ratio
  • Prevalence
  • Publication Bias
  • Sex Chromosome Aberrations*
  • Sex Chromosome Disorders of Sex Development*
  • Spermatogenesis / genetics

Supplementary concepts

  • Male sterility due to Y-chromosome deletions