SAP18

The encoded protein is a component of the SIN3 histone deacetylase complex that mediates transcriptional repression and also functions in the exon junction complex to regulate mRNA splicing, particularly inhibiting formation of proapoptotic splice variants. Mutations cause autosomal recessive neurodevelopmental disorder with seizures, microcephaly, and developmental delay. The gene shows moderate tolerance to loss-of-function variants (pLI 0.08, LOEUF 0.92), consistent with recessive inheritance.