Impact of partial DAZ1/2 deletion and partial DAZ3/4 deletion on male infertility

This study aims to investigate the effect of the partial DAZ1/2 deletion and partial DAZ3/4 deletion on male infertility through a comprehensive literature search. All case-control studies related to partial DAZ1/2 and DAZ3/4 deletions and male infertility risk were included in our study. Odd ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association and its precision, respectively. Eleven partial DAZ1/2 deletion and nine partial DAZ3/4 deletion studies were included. Partial DAZ1/2 deletion was significantly associated with male infertility risk in the overall analysis (ORs=2.58, 95%CI: 1.60-4.18, I(2)=62.1%). Moreover, in the subgroup analysis stratified by ethnicity, partial DAZ1/2 deletion was significantly associated with male infertility risk in the East Asian populations under the random effect model (ORs=2.96, 95%CI: 1.87-4.71, I(2)=51.3%). Meanwhile, the analysis suggested that partial DAZ3/4 deletion was not associated with male infertility risk in East-Asian ethnicity (ORs=1.02, 95%CI: 0.54-1.92, I(2)=71.3%), but not in Non-East Asian under the random effect model (ORs=3.56, 95%CI: 1.13-11.23, I(2)=0.0%,). More interestingly, partial DAZ1/2 deletion was associated with azoospermia (ORs=2.63, 95%CI: 1.19-5.81, I(2)=64.7%) and oligozoospermia (ORs=2.53, 95%CI: 1.40-4.57, I(2)=51.8%), but partial DAZ3/4 deletion was not associated with azoospermia (ORs=0.71, 95%CI: 0.23-2.22, I(2)=71.7%,) and oligozoospermia (ORs=1.21, 95%CI: 0.65-2.24, I(2)=55.5%). In our meta-analysis, partial DAZ1/2 deletion is a risk factor for male infertility and different ethnicities have different influences, whereas partial DAZ3/4 deletion has no effect on fertility but partial DAZ3/4 deletion might have an impact on Non-East Asian male.