CWC27 is located at 5q12.3 and encodes a cyclophilin peptidyl-prolyl cis-trans isomerase. CWC27 has been shown, in vitro, to not exhibit the isomerase activity but is capable of binding proline. The C-terminal end of CWC27 has been shown to interact with CWC22 to form a landing platform for a core component of the exon junction complex. CWC27 is a splicing factor in the Bact spliceosome complex.
Mutations in CWC27 are detected across the gene (NM_005869.3) and are predicted to cause protein truncations by nonsense variants or frame shift variants. Xu M et al. found that there is a genotype-phenotype correlation, with more severe phenotypes correlating with variants closer to the N-terminus.
Xu M et al. identified c.943G.T (p.Glu315*), causing a premature truncation of the protein and a syndromic form of RP in the homozygous state; c.495G>A (p.Leu167Glyfs*3), causing a premature truncation of the protein and a syndromic form of RP in the homozygous state; c.1002dupA (p.Val335Serfs*13), causing a premature truncation of the protein and RP in the homozygous state; c.599+1G>A (p.[Val166Lysfs*3; Val191Lysfs*3]), causing a premature truncation of the protein and a syndromic form of retinal degeneration (flat ERG) in the homozygous state; c19C>T (p.Gln7*) and c.427C>T (p.Arg143*), causing premature truncation of the proteins and syndromic disease (with no retinal involvement detected at 2 months of age) in the compound heterozygous state; c.617C>A (p.Ser206*), causing premature truncation of the protein and causing a syndromic form of LCA in the compound heterozygous state with c.1002dupA.
Brea-Fernández AJ et al. identified c.355C>T (p.Arg119*), causing a premature truncation of the protein and a syndromic form of RP in the homozygous state.