mutation causes female infertility with large polar body oocytes.

The Moloney sarcoma oncogene ( encodes a protein serine/threonine kinase and is expressed at high levels in oocytes undergoing meiotic maturation. The MOS/MAPK pathway is normally required for the maintenance of microtubules and chromatin in a metaphasic state during the meiotic divisions. To determine the pathogenic genes in a female infertile patient due to large polar body oocytes, whole-exome sequencing was performed on the patient and available family members. We identified a novel homozygous missense mutation c.591T > G in . Bioinformatics analysis showed that the mutation is harmful. These findings suggest that mutation results in oocytes with a large polar body and poor embryonic development in patients. The variant may regulate oocyte asymmetric division by MAPK/WAVE2/Arp2/3/actin signaling pathway. This will help to understand the comprehensive role of MOS in early human reproductive process and provide genetic markers for future genetic counseling for more individualized treatments.