PQBP1 and Renpenning syndrome: Renpenning syndrome disease-linked frameshift mutations in the PRD, and particularly a missense mutant with a point mutation in the WW domain (Y65C), lost association with splicing-related factors, e.g., the central U2 small nuclear ribonucleoprotein (snRNP) component SF3B1, suggesting that the complex of SF3B1 and PQBP1 influences splicing decisions on a subset of mRNAs [32].