Mutations in MSH5 in primary ovarian insufficiency

Area of Science:

• Genetics
• Reproductive Biology
• Molecular Biology

Background:

• Primary ovarian insufficiency (POI) is a genetically diverse condition with familial and sporadic occurrences.
• Understanding the genetic basis of POI is crucial for diagnosis and potential treatments.

Purpose of the Study:

• To identify novel genetic causes of primary ovarian insufficiency (POI).
• To investigate the role of the MSH5 gene in POI pathogenesis.
• To explore the functional consequences of MSH5 mutations on DNA repair.

Main Methods:

• Whole exome sequencing was performed on a Chinese pedigree with POI.
• A homologous mutation was created in mice to study its effects.
• In vitro functional studies assessed the impact of mutant MSH5 on DNA homologous recombination repair.
• Sanger sequencing was used to screen MSH5 in sporadic POI patients.

Main Results:

• A novel homozygous missense mutation in the MSH5 gene (p.D487Y) was identified in sisters with POI.
• The homologous mutation in mice led to ovaries lacking oocytes.
• Mutant MSH5 was found to impair DNA homologous recombination repair.
• Three heterozygous MSH5 mutations were identified in sporadic POI patients, but their causality requires further investigation.

Conclusions:

• Genetic mutations in the MSH5 gene can cause primary ovarian insufficiency (POI).
• Impaired DNA damage repair mechanisms, specifically homologous recombination, are implicated in non-syndromic POI.
• This study underscores the importance of DNA repair pathways in ovarian function and POI etiology.