POU4F1 and Waardenburg-Shah syndrome: These include POU4F1, associated with childhood-onset ataxia and hypotonia syndrome (OMIM #619352); FBXL3, associated with intellectual developmental disorder with short stature, facial anomalies, and speech defects (OMIM #606220); and EDNRB, which can cause Waardenburg syndrome type IV in both dominant and recessive contexts (OMIM #277580).