title: Transforming growth factor beta 1 869T/C and 915G/C polymorphisms and risk of autism spectrum disorders.
abstract: BACKGROUND
  Transforming growth factor-β1 (TGF-β1) has been found to play a crucial role in early central nervous system development. Several studies have illustrated decreased TGF-β1 levels in sera and brains of autistic children. Two point mutations in the TGF-β1 signal peptide at 869T/C and 915G/C have been reported to influence TGF-β1 expression. The aim of the present study was to investigate the correlation of TGF-β1 polymorphisms and their haplotypes with autism.
  
  
  METHODS
  This study was performed on 39 autistic patients and 35 age- and sex-matched normal controls in an Iranian population, using the sequence specific primed-polymerase chain reaction (PCR-SSP) technique. Patients were divided into mild-to-moderate and severe groups according to the childhood autism rating scale.
  
  
  RESULTS
  No significant differences were observed for allele, genotype, or haplotype frequencies between the autistics and controls. Only a slight difference was observed in GC25 between the controls and all children with autism.
  
  
  CONCLUSIONS
  Thus, these results indicate that the polymorphisms in TGF-β1 gene may not play an important role in the development of autism.
authors.affiliation: Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Immunology, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Khakzad
authors.affiliation: Immunology Research Center, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Salari
authors.affiliation: Department of Psychiatrics, Islamic Azad University, Mashhad Branch, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Javanbakht
authors.affiliation: Noor Hedayat Center of Autism Spectrum Disorders, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Hojati
authors.affiliation: Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Abdolreza
authors.initials: A
authors.lastname: Varasteh
authors.affiliation: Immunology Research Center, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Sankian
authors.affiliation: Department of Biostatistc, Shahid Beheshti University of medical sciences, Tehran, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Meshkat
keywords: Autism spectrum disorders; Development; Polymorphism; Transforming Growth Factor beta 1