The Study Of GSH Related Factors And Oxidative Stress In Autism Children

Objective:This study aims to investigate the influence of heavy metal lead level in autistic children, the glutathione biological metabolism index and the corresponding genetic diversity in autism, and then discuss the role of oxidative stress in pathogenesis of autism children. It provides a basis for the study of the etiology of autism. Method:(1) Study the effect of heavy metal lead level in autistic children:Participants were from six special education schools and a private autism early intervention training institution. There were autism group(53 cases) and low intelligence group(105 cases). We used ultraviolet spectrophotometer to detect the urine δ-aminolevulinic acid(δ-ALA) level of the two groups, t test analyzed the δ-ALA levels of the two groups. The correlation between δ-ALA levels and characteristics of autism was analyzed.(2) Study the relation of glutathione biological metabolism indexes with autism: Cases were autistic children diagnosed(30 cases); Control children(66 cases) were healthy children. We used the microtitration assay to detect the reduced glutathione(GSH), total glutathione(TGSH) and oxidized glutathione(GSSG) in serum of the two groups, and use ultraviolet spectrophotometer to detect the activity of glutathione s-transferase(GST) in autism group and normal group. T test analyzed the levels of GSH, TGSH, GSSG, and GST of the two groups.(3) Study glutathione related genotypes in children with autism: Cases(76 cases) were autism from five special education schools and a private autism early intervention training institution; Control children(72 cases) were normal children in a kindergarten of Tianjin. Use oral swabs to extract DNA. PCR was utilized to detect GSTM1 and GSTT1 gene polymorphism, χ2 test analyzed genotype frequency. T test and ANOVA analyzed the correlation between gene polymorphism and serum GST levels, then analyzed the correlation between gene polymorphism and characteristics in autism.(4) All analyses were carried out using SPSS17.0, α=0.05. Result:(1) Study the effect of heavy metal lead level in autistic children: Urine δ-ALA levels of autistic children and low intelligence children were both higher than the normal reference value, and there was significant difference between the two groups(P<0.05). There was no significant difference between autistic children and low intelligence children in urine δ-ALA levels(P>0.05); comparing urine δ-ALA levels by age 1:1 and age, gender ratio of frequency, there was still no significant difference(P>0.05). We found an association in autistic children between the urine δ-ALA levels and nonverbal communication measured by CARS scores(r=0.273, P=0.048).(2)Study the relation of glutathione biological metabolism indexes with autism: The serum levels of GSH, TGSH and the ratio of GSH/GSSG in cases were lower than their age-matched controls(P<0.05); the serum levels of GSSG were higher than normal group(P<0.05). There was no significant difference between the two group of serum GST(P>0.05).(3)Study glutathione related genotypes in children with autism: There were no significant differences in the distribution of GSTM1, GSTT1 and joint genotype between autistic and control subjects(both P>0.05). GST activity levels in GSTM1(null) autism were lower than GSTM1(+/+) group, and there was significant difference(P<0.05). GST activity levels had significant difference in three groups of joint genotype(P<0.05). ANOVA analyzed correlation between gene polymorphism and ABC, CARS in autism, but showed no significant difference(P>0.05). Conclusion:(1) As an important exogenous oxide, heavy metal lead may have influence on autism prevalence and social skills.(2)Oxidative stress is closely related to the occurrence of autism. GSH, GSSG and TGSH can be used as important markers of oxidative stress. Increased serum GSSG and decreased GSH and TGSH levels may be one of the important factors in onset of autism.(3) GSTM1 gene expression may affect the activity of GST. There was no association between autism, autism behavior and GSTM1, GSTT1 genotype.