FTO and oligospermia: To evaluate the potential function of FTO in human fertility, whole-exome sequencing (WES) data for patients with oligospermia and NOA (total 1001) were utilized to screen for loss-of-function mutations in FTO. We identified a heterozygous nonsense mutation (NP_001073901: c.964C>T, p. Arg322∗) in patients with NOA and a heterozygous frameshift mutation (NP_001073901: c.1277delT, p. Leu426fs) in patients with oligospermia.