Biallelic Mutations in PATL2 Cause Female Infertility Characterized by Oocyte Maturation Arrest

Oocyte maturation arrest results in female infertility, but the genetic determinants of human oocyte maturation arrest remain largely unknown. Previously, we identified TUBB8 mutations responsible for human oocyte maturation arrest, indicating the important role of genetic factors in the disorder. However, TUBB8 mutations account for only around 30% of individuals with oocyte maturation arrest; thus, the disorder is likely to involve other genetic factors that are as yet unknown. Here, we initially identified a homozygous nonsense mutation of PATL2 (c.784C>T [p. Arg262*]) in a consanguineous family with a phenotype characterized by human oocyte germinal vesicle (GV) arrest. Subsequent mutation screening of PATL2 in a cohort of 179 individuals identified four additional independent individuals with compound-heterozygous PATL2 mutations with slight phenotypic variability. A genetic burden test further confirmed the genetic contribution of PATL2 to human oocyte maturation arrest. By western blot in HeLa cells, identification of splicing events in affected individuals' granulosa cells, and immunostaining in affected individuals' oocytes, we provide evidence that mutations in PATL2 lead to decreased amounts of protein. These findings suggest an important role for PATL2 mutations in oocyte maturation arrest and expand our understanding of the genetic basis of female infertility.