MSH4 and primary ovarian failure: The MSH4 gene (MutS Protein Homolog 4, OMIM: 602105) encodes for a meiosis-specific protein that is involved in DNA mismatch correction and is required for reciprocal recombination and proper segregation of homologous chromosomes at meiosis I. Biallelic variants are associated with premature ovarian failure and spermatogenic failure.