Catechol-O-Methyltransferase (COMT) Val(108/158 )Met polymorphism does not modulate executive function in children with ADHD

BACKGROUND: An association has been observed between the catechol-O-methyltransferase (COMT) gene, the predominant means of catecholamine catabolism within the prefrontal cortex (PFC), and neuropsychological task performance in healthy and schizophrenic adults. Since several of the cognitive functions typically deficient in children with Attention Deficit Hyperactivity Disorder (ADHD) are mediated by prefrontal dopamine (DA) mechanisms, we investigated the relationship between a functional polymorphism of the COMT gene and neuropsychological task performance in these children. METHODS: The Val(108/158 )Met polymorphism of the COMT gene was genotyped in 118 children with ADHD (DSM-IV). The Wisconsin Card Sorting Test (WCST), Tower of London (TOL), and Self-Ordered Pointing Task (SOPT) were employed to evaluate executive functions. Neuropsychological task performance was compared across genotype groups using analysis of variance. RESULTS: ADHD children with the Val/Val, Val/Met and Met/Met genotypes were similar with regard to demographic and clinical characteristics. No genotype effects were observed for WCST standardized perseverative error scores [F(2,97 )= 0.67; p > 0.05], TOL standardized scores [F(2,99 )= 0.97; p > 0.05], and SOPT error scores [F(2,108 )= 0.62; p > 0.05]. CONCLUSIONS: Contrary to the observed association between WCST performance and the Val(108/158 )Met polymorphism of the COMT gene in both healthy and schizophrenic adults, this polymorphism does not appear to modulate executive functions in children with ADHD

Modulation of executive function in children with Attention DeficitHyperactivity Disorder by allelic variants of the catechol-O-methyltransferase gene and three varying doses of methylphenidate

An association has been observed between the catechol-O-methyltransferase (COMT) gene, the predominant means of catecholamine catabolism within the prefrontal cortex (PFC), and neuropsychological task performance in healthy and schizophrenic adults. Since several of the cognitive functions typically deficient in children with Attention Deficit Hyperactivity Disorder (ADHD) are mediated by prefrontal dopamine (DA) mechanisms, we investigated the relationship between a functional polymorphism of the COMT gene and neuropsychological task performance in these children. Furthermore, since methylphenidate (MPH), the primary pharmacological drug in ADHD, may exert its effects, at least in part, through PFC dopaminergic pathways, we investigated the relationship between the COMT polymorphism and acute neuropsychological and behavioural response to three varying doses of MPH. Children with ADHD showed improvement on measures of both cognitive and motor behaviours under MPH, although improvement within each functional domain appeared to follow distinctive dose-response patterns possibly reflecting different neurobiological pathways. No genotype effects were observed on any measures of cognitive or motor behaviour or on the response of cognitive or motor behaviours to MPH

HIV Prophylaxis in High Risk Newborns: An Examination of Sociodemographic Factors in an Inner City Context

Background. Perinatal HIV transmission is less than 1% with antiretroviral (ARV) prophylaxis. Transmission risk appears higher in “high risk” dyads, yet this is not well defined, possibly exposing more infants to combination ARV compared with standard care. Objective. To describe characteristics of mother-infant dyads where infants received ARVs and how these characteristics relate to specific ARV regimens. Methods. Retrospective chart review of ARV-receiving newborns at St. Michael’s Hospital from 2007 to 2012 (and their mothers). Numerical and categorical variables were analyzed using t-tests/ANOVA F-tests and Fisher’s exact tests, respectively. Results. Maternal HIV status at delivery was as follows: 69% positive and 24% unknown. Maternal factors significantly associated with newborn-triple therapy are Canadian origin, substance abuse, unstable housing, lost custody of previous children, and sex work. Neonatal factors are child protective services involvement, NICU, and lengthier admission. Maternal factors associated with monotherapy are African origin, HIV-positive, employment, and education. Further analysis based on maternal presentation at delivery demonstrated unequal distribution of many aforementioned factors. Discussion. This cohort revealed associations between particular factors and newborn-monotherapy or triple therapy that exist, suggesting that sociodemographic factors may influence the choice of ARV regimen. Canadian perinatal HIV transmission guidelines should qualify how to risk stratify newborns and consider use of rapid HIV antibody testing

HIV Prophylaxis in High Risk Newborns: An Examination of Sociodemographic Factors in an Inner City Context

Background. Perinatal HIV transmission is less than 1% with antiretroviral (ARV) prophylaxis. Transmission risk appears higher in “high risk” dyads, yet this is not well defined, possibly exposing more infants to combination ARV compared with standard care. Objective. To describe characteristics of mother-infant dyads where infants received ARVs and how these characteristics relate to specific ARV regimens. Methods. Retrospective chart review of ARV-receiving newborns at St. Michael’s Hospital from 2007 to 2012 (and their mothers). Numerical and categorical variables were analyzed using -tests/ANOVA -tests and Fisher’s exact tests, respectively. Results. Maternal HIV status at delivery was as follows: 69% positive and 24% unknown. Maternal factors significantly associated with newborn-triple therapy are Canadian origin, substance abuse, unstable housing, lost custody of previous children, and sex work. Neonatal factors are child protective services involvement, NICU, and lengthier admission. Maternal factors associated with monotherapy are African origin, HIV-positive, employment, and education. Further analysis based on maternal presentation at delivery demonstrated unequal distribution of many aforementioned factors. Discussion. This cohort revealed associations between particular factors and newborn-monotherapy or triple therapy that exist, suggesting that sociodemographic factors may influence the choice of ARV regimen. Canadian perinatal HIV transmission guidelines should qualify how to risk stratify newborns and consider use of rapid HIV antibody testing.Peer Reviewe

HIV Prophylaxis in High Risk Newborns: An Examination of Sociodemographic Factors in an Inner City Context

Background. Perinatal HIV transmission is less than 1% with antiretroviral (ARV) prophylaxis. Transmission risk appears higher in "high risk" dyads, yet this is not well defined, possibly exposing more infants to combination ARV compared with standard care. Objective. To describe characteristics of mother-infant dyads where infants received ARVs and how these characteristics relate to specific ARV regimens. Methods. Retrospective chart review of ARV-receiving newborns at St. Michael's Hospital from 2007 to 2012 (and their mothers). Numerical and categorical variables were analyzed using -tests/ANOVA -tests and Fisher's exact tests, respectively. Results. Maternal HIV status at delivery was as follows: 69% positive and 24% unknown. Maternal factors significantly associated with newborn-triple therapy are Canadian origin, substance abuse, unstable housing, lost custody of previous children, and sex work. Neonatal factors are child protective services involvement, NICU, and lengthier admission. Maternal factors associated with monotherapy are African origin, HIV-positive, employment, and education. Further analysis based on maternal presentation at delivery demonstrated unequal distribution of many aforementioned factors. Discussion. This cohort revealed associations between particular factors and newborn-monotherapy or triple therapy that exist, suggesting that sociodemographic factors may influence the choice of ARV regimen. Canadian perinatal HIV transmission guidelines should qualify how to risk stratify newborns and consider use of rapid HIV antibody testing

Catechol-O-Methyltransferase (COMT) Val108/158 Met polymorphism does not modulate executive function in children with ADHD

BACKGROUND:An association has been observed between the catechol-O-methyltransferase (COMT) gene, the predominant means of catecholamine catabolism within the prefrontal cortex (PFC), and neuropsychological task performance in healthy and schizophrenic adults. Since several of the cognitive functions typically deficient in children with Attention Deficit Hyperactivity Disorder (ADHD) are mediated by prefrontal dopamine (DA) mechanisms, we investigated the relationship between a functional polymorphism of the COMT gene and neuropsychological task performance in these children.METHODS:The Val108/158 Met polymorphism of the COMT gene was genotyped in 118 children with ADHD (DSM-IV). The Wisconsin Card Sorting Test (WCST), Tower of London (TOL), and Self-Ordered Pointing Task (SOPT) were employed to evaluate executive functions. Neuropsychological task performance was compared across genotype groups using analysis of variance.RESULTS:ADHD children with the Val/Val, Val/Met and Met/Met genotypes were similar with regard to demographic and clinical characteristics. No genotype effects were observed for WCST standardized perseverative error scores [F2,97 = 0.67; p > 0.05], TOL standardized scores [F2,99 = 0.97; p > 0.05], and SOPT error scores [F2,108 = 0.62; p > 0.05].CONCLUSIONS:Contrary to the observed association between WCST performance and the Val108/158 Met polymorphism of the COMT gene in both healthy and schizophrenic adults, this polymorphism does not appear to modulate executive functions in children with ADHD