Oocyte maturation defect is an extremely rare primary infertility, which is characterized by ovum development arrest, oocyte complete fertilization failure, oocyte apoptosis before and after fertilization, and early embryonic development arrest. This case explored the genetic etiology of a primary infertility patient, who had no mature oocyte after two cycles of controlled ovarian hyperstimulation. Peripheral blood samples of the patient were collected for whole exome sequencing, the suspected pathogenic variants were screened by bioinformatics and verified by sanger sequencing on the patient and her parents. Results showed that the patient was found to harbor homozygous variant of the PATL2 gene, namely c.1363C>T (p.Gln455*). Sanger sequencing has verified that the parents are both heterozygous. The mutation of c.1363C>T is a rare pathogenic mutation that had not yet been recorded in HGMD database. In this case, PATL2 gene mutation can cause oocyte maturation arrest, it is recommended to use whole exome sequencing and genetic counseling as soon as possible for these patients, so as to select appropriate treatment.

Oocyte maturation defect is an extremely rare primary infertility, which is characterized by ovum development arrest, oocyte complete fertilization failure, oocyte apoptosis before and after fertilization, and early embryonic development arrest. This case explored the genetic etiology of a primary infertility patient, who had no mature oocyte after two cycles of controlled ovarian hyperstimulation. Peripheral blood samples of the patient were collected for whole exome sequencing, the suspected pathogenic variants were screened by bioinformatics and verified by sanger sequencing on the patient and her parents. Results showed that the patient was found to harbor homozygous variant of the PATL2 gene, namely c.1363C>T (p.Gln455*). Sanger sequencing has verified that the parents are both heterozygous. The mutation of c.1363C>T is a rare pathogenic mutation that had not yet been recorded in HGMD database. In this case, PATL2 gene mutation can cause oocyte maturation arrest, it is recommended to use whole exome sequencing and genetic counseling as soon as possible for these patients, so as to select appropriate treatment.