tretinoin and Smith-Magenis-Syndrome

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.

Topics: Headache; Humans; Mutation; Phenotype; Schizophrenia; Smith-Magenis Syndrome; Trans-Activators; Transcription Factors; Tretinoin

Hyperexcitability of brain circuits is a common feature of autism spectrum disorders (ASDs). Genetic deletion of a chromatin-binding protein,

Topics: Animals; Chromatin; Disease Models, Animal; Hippocampus; Mice; Phenotype; Seizures; Smith-Magenis Syndrome; Trans-Activators; Tretinoin

Smith-Magenis syndrome (SMS) is a neurodevelopmental disorder characterized by cognitive and behavioral symptoms, obesity, and sleep disturbance, and no therapy has been developed to alleviate its symptoms or delay disease onset. SMS occurs due to haploinsufficiency of the retinoic acid-induced-1 (RAI1) gene caused by either chromosomal deletion (SMS-del) or RAI1 missense/nonsense mutation. The molecular mechanisms underlying SMS are unknown. Here, we generated and characterized primary cells derived from four SMS patients (two with SMS-del and two carrying RAI1 point mutations) and four control subjects to investigate the pathogenetic processes underlying SMS. By combining transcriptomic and lipidomic analyses, we found altered expression of lipid and lysosomal genes, deregulation of lipid metabolism, accumulation of lipid droplets, and blocked autophagic flux. We also found that SMS cells exhibited increased cell death associated with the mitochondrial pathology and the production of reactive oxygen species. Treatment with N-acetylcysteine reduced cell death and lipid accumulation, which suggests a causative link between metabolic dyshomeostasis and cell viability. Our results highlight the pathological processes in human SMS cells involving lipid metabolism, autophagy defects and mitochondrial dysfunction and suggest new potential therapeutic targets for patient treatment.

Topics: Autophagy; Haploinsufficiency; Humans; Lipid Metabolism; Lipids; Phenotype; Smith-Magenis Syndrome; Trans-Activators; Transcription Factors; Tretinoin