RESUMO
Research has implicated mutations in the gene for neurexin-1 (NRXN1) in a variety of conditions including autism, schizophrenia, and nicotine dependence. To our knowledge, there have been no published reports describing the breadth of the phenotype associated with mutations in NRXN1. We present a medical record review of subjects with deletions involving exonic sequences of NRXN1. We ascertained cases from 3,540 individuals referred clinically for comparative genomic hybridization testing from March 2007 to January 2009. Twelve subjects were identified with exonic deletions. The phenotype of individuals with NRXN1 deletion is variable and includes autism spectrum disorders, mental retardation, language delays, and hypotonia. There was a statistically significant increase in NRXN1 deletion in our clinical sample compared to control populations described in the literature (P = 8.9 x 10(-7)). Three additional subjects with NRXN1 deletions and autism were identified through the Homozygosity Mapping Collaborative for Autism, and this deletion segregated with the phenotype. Our study indicates that deletions of NRXN1 predispose to a wide spectrum of developmental disorders.
Assuntos
Deficiências do Desenvolvimento/genética , Transtorno Autístico/genética , Criança , Transtornos Globais do Desenvolvimento Infantil/genética , Hibridização Genômica Comparativa , Feminino , Humanos , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Masculino , Mutação , Fenótipo , Esquizofrenia/genética , Deleção de SequênciaRESUMO
Neonatal seizures associated with white-matter changes on neuroimaging suggest an etiology of hypoxic-ischemic encephalopathy. Metabolic and idiopathic etiologies are also considerations but are less likely. Despite the fact that two disorders associated with neonatal seizures are diagnosed by cerebrospinal fluid neurotransmitter analysis, such an analysis is not standard in the work-up for idiopathic neonatal seizures. We describe an infant who had a prolonged delivery, seizures on the first day of life, and white-matter changes on neuroimaging. A progressive seizure disorder that was refractory to standard antiepilepsy medications developed at 2 months of age. Analysis of cerebrospinal fluid neurotransmitters at that time demonstrated a pattern consistent with folinic acid-responsive seizures. Seizures ceased 24 hours after starting folinic acid. Serial neuroimaging, electroencephalograms, and metabolic changes from this patient are presented. This case illustrates the importance of cerebrospinal fluid neurotransmitter analysis as part of the work-up for idiopathic neonatal seizures.