Assignment of the human postmeiotic segregation increased (S. cerevisiae) 1 (PMS1) to chromosome 2q31.1 by radiation hybrid mapping.

The human PMS1 gene encodes the prokaryotic mutL homolog implicated in DNA damage repair and homologous recombination. The PMS1 cDNA was isolated and characterized by Nicolaides et al. (1994) and the 5) region by Yanagisawa et al. (1998). The promotor region had multiple splice and transcriptional start sites. PMS1 forms a complex with MSH2 and MLH1 during initiation of mismatch repair of simple repetitive sequences (Prolla et al., 1994). Mutations in one of these components leads to a 100–700 fold increase in instability of the repetitive sequences (Strand et al., 1993). Mutations in PMS1 have been found in hereditary non-polyposis colon cancer (HNPCC) (Nicolaides et al., 1994). PMS1 was initially localized to chromosome 2 by somatic cell hybrids (Papadopulous et al., 1994) and later to 2q31→q33 by FISH (Nicolaides et al., 1994).