PRKACB and familial atrioventricular septal defect: We identified a de novo missense variant in PRKACB on ES re-analysis in an individual with ID, refractory focal epilepsy, spasticity, periventricular nodular heterotopia, a common atrium / AVSD, polydactyly and several tumours (benign ovarian tumour, liver haemangioma and renal cell carcinoma).