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

•Impact of partial DAZ deletion on male infertility was studied.•Partial DAZ1/2 deletion was associated with male infertility.•Partial DAZ3/4 deletion was not related with male infertility in East Asian ethnicity.•Partial DAZ1/2 deletion was associated with azoospermia and oligozoospermia.•Partial DAZ3/4 deletion was not associated with azoospermia and oligozoospermia.

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, I2 = 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, I2 = 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, I2 = 71.3%), but not in Non-East Asian under the random effect model (ORs = 3.56, 95%CI: 1.13–11.23, I2 = 0.0%,). More interestingly, partial DAZ1/2 deletion was associated with azoospermia (ORs = 2.63, 95%CI: 1.19–5.81, I2 = 64.7%) and oligozoospermia (ORs = 2.53, 95%CI: 1.40–4.57, I2 = 51.8%), but partial DAZ3/4 deletion was not associated with azoospermia (ORs = 0.71, 95%CI: 0.23–2.22, I2 = 71.7%,) and oligozoospermia (ORs = 1.21, 95%CI: 0.65–2.24, I2 = 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.