Novel homozygous mutation in TUBB8 associated with oocyte maturation defect-2 in a consanguineous marriage family

Purpose: To study the genetic basis of oocyte maturation defects, we performed clinical and genetic analysis of a pedigree. Variations in many genes may lead to the occurrence of oocyte maturation defects, but the specific functional mechanisms need to be further studied.Methods: One proband with oocyte maturation defect-2 receiving ovulation induction therapy and her parents were selected for clinical detection, whole exome sequencing and Sanger sequencing. One normal woman received ovulation induction therapy. Mutations were assessed after frequency screening of public exome databases. Then homozygous variants shared by the proband and her parents were selected.Results: Arrest of oocytes maturation was observed. A new missense mutation in TUBB8 (TUBB8: NM_177987: exon 2: c. C161T: p. A54V) was identified, which was shown to be novel compared with public databases. The variant was highly conserved among primates, and was suggested to be deleterious by online software prediction. Conclusions: The homozygote of this variant (TUBB8: NM_ 177987: exon 2:c.C161T: p.A54V) might affect spindle assembly, cause arrest of oocyte maturation and lead to oocyte maturation defect-2.