system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, METHODS, RESULTS. Meshes: Attention Deficit Disorder with Hyperactivity, Case-Control Studies, Child, Diagnostic and Statistical Manual of Mental Disorders, Dopamine Plasma Membrane Transport Proteins, Family, Gene Frequency, Genetic Predisposition to Disease, Genotype, Humans, Minisatellite Repeats, Polymerase Chain Reaction, Polymorphism, Genetic, Receptors, Dopamine D4, Risk Factors.
user
Is [ Combination of DRD4 and DAT1 genotypes an important risk factor for attention deficit disorder with hyperactivity families living in Santiago , Chile ]? Context: Attention deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness, and/or inattentiveness. To search for possible associations between dopamine receptor D4 (DRD4) and dopamine transponder 1 (DATl) polymorphisms and ADHD in Chilean families. We extended a previous family-based discordant sib pair analysis that included 26 cases diagnosed according to DSM-IV criteria and 25 controls (healthy siblings of cases), adding 14 cases and 11 controls. Both loci, individually classified as homozygotes or heterozygotes for the DRD4 7-repeat and DATl 10-repeat alleles, did not exhibit genotype frequency differences between affected children and their healthy siblings. However, the simultaneous presence of both DRD4 7-repeat heterozygosity and DATl 10 allele homozygosity was significantly higher (22.5%) in cases (40), compared with (2.8%) unaffected siblings (36), with an odds-ratio of 10.16.
assistant
The genotype combination DRD4/7 heterozygotes and DAT1/10 homozygotes is a high risk factors in Chilean families for ADHD. Increased density of dopamine transporters in ADHD brains, along with abundance of 7-repeat D4 receptors in prefrontal cortex, which is impaired in ADHD patients, make the observed gene-gene interaction worthy of studies to understand the functional basis of ADHD. Final Decision: yes