A de novo mutation (p.S1419F) of Retinoic acid induced 1 is responsible for a patient with Smith-Magenis syndrome exhibiting schizophrenia

Smith-Magenis syndrome (SMS, OMIM# 182290) is a rare congenital disorder which characterized by multiple abnormalities involving in craniofacial, skeletal, otorhinolaryngolocial, neurological, behavioral and others. 17p11.2 microdeletion and RAI1 mutations have been proven to be genetic lesions of this disease. However, the relationship between RAI1 variants and different phenotypes is still unclear. The discoveries of more RAI1 mutations in patients with different phenotypes will help to elucidate the pathogenesis of the RAI1 gene. Here, we describe a young patient with schizophrenia and headache as the main clinical presentation, with SMS-like features including depression, sleep disturbance and pain-free status. Whole exome sequencing and Sanger sequencing suggested that a de novo mutation (NM_030665.3: c.4256C > T/p.S1419F) of RAI1 may be the genetic lesion of the patient. The bioinformatic program predicted that the new mutation (p.S1419F), located in an evolutionarily conserved site of RAI1, was deleterious. Further, western blot analysis suggested that the novel mutation may decrease the protein levels of RAI1 in the patient. Hence, we reported a novel mutation of RAI1 in a patient with SMS, schizophrenia and headache. Our study may expand the spectrum of RAI1 mutations which may further contribute to the mechanisms underlying SMS, schizophrenia and headache.