William Cornejo Ochoa

Genome-wide association study of Tourette's syndrome

Tourettes syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (P<5 × 10−8); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (P=1.85 × 10−6). A secondary analysis including an additional 211 cases and 285 controls from two closely related Latin American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (P=3.6 × 10−7 for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder.

Prevalence and Clinical Characteristics of the Restless Legs Syndrome (RLS) in Patients Diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) in Antioquia

Introduction: Attention Deficit Hyperactivity Disorder (ADHD) is the most common behavioral issue for children. One of the sleeping disorders most frequently related to ADHD is the Restless Legs Syndrome (RLS), characterized by an irresistible urge to move the legs, something that is generally associated with paresthesias and motor restlessness. The prevalence rate of RLS in children diagnosed with ADHD is close to 18%, but in Colombia, these cases have been hardly studied. Objective: To determine the frequency of RLS, in children with ADHD. Methods: A cross-sectional study, filled out by parents of children diagnosed with ADHD, were analyzed. This questionnaire contained clinical criteria for classifying ADHD according to the DSM-IV, as well as diagnostic criteria for RLS by the National Institutes of Health (2003). Results: A predominance rate of 65.6% in combined ADHD was observed in children with RLS criteria. Upon carrying out an exploratory data analysis, it was found that having a family history of RLS and belonging to the middle or low socioeconomic strata are conditions associated with the presence of RLS in children with ADHD, with a significant p (p < 0.000) and a PR of 4.47 (3.16-6.32). Conclusions: The prevalence of RLS was similar to the findings of other clinical investigations. However, it highlights new prevalence values in relation to the comorbidity between ADHD and RLS, suggesting the need for new clinical and therapeutic alternatives amidst the presence of both syndromes.