Glutathione S-transferases (GST) are involved in the detoxification of exogenous chemicals including lead (Pb). Using data from 344 pairs of autism spectrum disorder (ASD) cases and age- and sex-matched typically developing (TD) controls (2–8 years old) from Jamaica, we investigated the interaction between three GST genes and ASD status as determinants of blood Pb concentrations (BPbCs). We found that ASD cases had lower geometric mean BPbCs than TD children (1.74 vs. 2.27 µg/dL, p < 0.01). Using a co-dominant genetic model, ASD cases with the Ile/Val genotype for the GSTP1 Ile105Val polymorphism had lower GM BPbCs than TD controls, after adjusting for a known interaction between GSTP1 and GSTT1, child’s parish, socioeconomic status, consumption of lettuce, fried plantains, and canned fish (Ile/Val: 1.78 vs. 2.13 µg/dL, p = 0.03). Similarly, among carriers of the I/I or I/D (I*) genotype for GSTT1 and GSTM1, ASD cases had lower adjusted GM BPbCs than TD controls (GSTT1 I*: 1.61 vs. 1.91 µg/dL, p = 0.01; GSTM1 I*: 1.71 vs. 2.04 µg/dL, p = 0.01). Our findings suggest that genetic polymorphisms in GST genes may influence detoxification of Pb by the enzymes they encode in Jamaican children with and without ASD.
Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with early onset in utero or childhood. Environmental exposure to six metals (Pb, Hg, As, Cd, Mn, Al) is believed to be associated with ASD directly or interactively with genes. Objective: To assess the association of ASD among Pakistani children with the six metals and genotype frequencies of three GST genes (GSTP1, GSTM1, GSTT1). Methods: We enrolled 30 ASD cases, age 2–12 years old, and 30 age- and sex-matched typically developing (TD) controls in Karachi, Pakistan. We assessed associations of ASD status with various factors using Conditional Logistic Regression models. We also used General Linear Models to assess possible interaction of blood Mn and Pb concentrations with the three GST genes in relation to ASD status. Results: The unadjusted difference between ASD and TD groups in terms of geometric mean blood Pb concentrations was marginally significant (p = 0.05), but for Al concentrations, the adjusted difference was marginally significant (p = 0.06). Conclusions: This is the first study reporting six blood metal concentrations of Pakistani children with ASD. Estimates provided for possible interactions of GST genes with Mn and Pb in relation to ASD status are valuable for designing future similar studies.
Background: Lack of physicians’ knowledge regarding mental health, including Autism Spectrum Disorder (ASD) could have adverse effects on affected individuals’ health and quality of life. The purpose of this study was to provide construct validity for a modified questionnaire in order to determine the self-reported competency for underlying sub-constructs in ASD, make inferences on perceived competence in ASD based on a sample of Romanian physicians, and identify physicians’ characteristics associated with these sub-domains of competency. Methods: For this survey, we modified a questionnaire that was used in Pakistan and Turkey, and administered it to a sample of 383 practicing physicians in Romania to assess their perceived competency regarding ASD. Exploratory factor analysis on 12 knowledge questions revealed five sub-domains: stigma, potential causes, children’s behavior, misconceptions, and educational needs associated with ASD knowledge. Using General Linear Models, we determined physicians’ characteristics that predict the total competency score and various competency sub-scores. Results: Seventy-five percent of the responding physicians were female and 30% had over 30 years practicing medicine. The majority (73–94%) of physicians have correctly responded to some basic questions regarding knowledge about ASD. We also found that younger physicians were more knowledgeable about potential causes of ASD than older physicians (Adjusted Mean Score (AMS): 2.90 vs. 2.18, P < 0.01), while older physicians knew more about the behavior of children with ASD (AMS: 0.64 vs. 0.37, P = 0.02). We found a significant interaction (P < 0.01) between television as source of ASD knowledge and city where the clinic is located in relation to knowledge of the physicians regarding stigma related to ASD. However, the total score was not associated with the variables associated with sub-domains. Conclusion: Using factor analysis, we demonstrated construct validity of five sub-domains related to Romanian physicians’ knowledge about ASD that include stigma, potential causes, behavior in ASD children, special education needs, and misconceptions related to ASD. The lack of significant association of the knowledge of physicians on ASD neither with the Psychiatry nor the Pediatric ward rotations at medical school may support the need for improving the curriculum on ASD in Romanian medical schools.