EFTUD2 and mandibulofacial dysostosis: Additionally, two of our patients had very narrow external auditory canals, consistent with abnormal branchial arch development during embryogenesis, also thought to be a process disturbed in mandibulofacial dysostosis and Nager syndromes; however, the facial dysmorphology of patients with PUF60 variants is far more subtle than in EFTUD2 and SF3B4-related phenotypes and mandibulofacial dysostosis was not present in the patients we report.