transforming growth factor beta 1 869t/c and 915g/c polymorphisms and risk of autism spectrum disorders

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. conclusion: thus, these results indicate that the polymorphisms in tgf-β1 gene may not play an important role in the development of autism.