[Ritscher-Schinzel syndrome caused by CCDC22 gene mutation: a case report].

A boy, aged 1 month, attended the hospital due to feeding difficulty and hypotonia. He had unusual facial features (prominent forehead, hypertelorism, ptosis of the lateral canthus, thin upper lip, and low-set ears), hypotonia, and a decreased score of neonatal behavioral neurological assessment. Heart ultrasound showed atrial septal defect. Cranial MRI showed widened supratentorial ventricle, cerebral cistern, and subarachnoid space. High-throughput whole-exome sequencing of the boy detected a hemizygous mutation, c.315_320delTGAGCG, in the CCDC22 gene, which came from his mother, while such mutation was not found in his father. The unusual facies, clinical manifestations, and inheritance pattern of this boy were consistent with the manifestations of Ritscher-Schinzel syndrome reported abroad. This is a report for the first time of a case of X-linked recessive Ritscher-Schinzel syndrome caused by the hemizygous mutation c.315_320delTGAGCG in the CCDC22 gene in Chinese population.