Evidence of an association between 10/10 genotype of DAT1 and endophenotypes of attention deficit/hyperactivity disorder.

INTRODUCTION: Genetic variance of attention deficit-hyperactivity disorder (ADHD) is a strong determinant of this disorder. The 40 base pairs (bp) variable number tandem repeat (VNTR) located in the 3' untranslated region (UTR) of DAT1 gene increases the expression of the dopamine transporter. Therefore, DAT1 has been associated with susceptibility to ADHD. OBJECTIVE: To determine the association between the VNTR of DAT1 and the phenotype of ADHD or its endophenotypes in a sample of children aged between 6 and 15 years from Bogotá. SUBJECTS AND METHODS: We selected 73 patients with ADHD and 54 controls. WISC test was applied in all subjects and executive functions were assessed. The VNTR of DAT1 was polymerase chain reaction-amplified. Data regarding population genetics and statistical analysis were obtained. Correlation and association tests between genotype and neuropsychological testing were performed. RESULTS: The DAT1 polymorphism was not associated with ADHD (P=.85). Nevertheless, the 10/10 genotype was found to be correlated with the processing speed index (P<.05). In the hyperactivity subtype, there was a genotypic correlation with some subtests of executive function (cognitive flexibility) (P≤.01). In the combined subtype, the 10/10 genotype was associated with verbal comprehension index of WISC (P<.05). CONCLUSIONS: A correlation was found between DAT1 VNTR and the subtest "processing speed index" of WISC and the subtest "cognitive flexibility" of executive functions. To our knowledge, this is the first report to assess DAT1 gene in a Colombian population.

[Urodynamic models in the analysis of pressure-flow studies in the adult male]. / Modelos urodinámicos en el análisis de los estudios presión-flujo del varón adulto.

OBJECTIVE: To determine which urodynamic model best describes lower urinary tract dynamics during the voiding phase. METHODS: A pressure-flow study was conducted in 211 adult males. The urodynamic data from the pressure-flow study were modelized to a multivariate analysis with a descriptive design. Three descriptive models of urethral resistance were proposed: a linear model that consisted of the detrusor pressure at the end of voiding and the pressure-flow plot slope, and two quadratic models with one parameter [urethral resistance average (URA)] or two parameters [opening detrusor pressure and passive urethral resistance ratio curvature (PURR)]. Bladder contractility was defined by two parameters: power at maximum flow rate (Pw) and maximum power/bladder surface (Wmax). Voiding volume was included in all models as control variable. The best model was defined as that which explains a higher percentage of observed maximum urinary flow rate, the most widely utilized datum in the urodynamic studies of the adult male. RESULTS: The model that consisted of the URA and Pw was found to be the best. We observed an interaction between URA and voiding volume (at higher voiding volume the decrease of the maximum urinary flow due to URA was found to be greater). CONCLUSIONS: The URA was found to be the parameter that best describes urethral pressure. Variations in the maximum urinary flow rate is better described by the Pw than by the Wmax.