ABSTRACT
Background: Attention deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness, and/or inattentiveness. Aún: To search forpossible associations between dopamine receptor D4 (DRD4) and dopamine transponer 1 (DATl) polymorphisms and ADHD in Chilean families. Material and methods: We extended a previous family-based discordant sib pair analysis that included 26 cases diagnosed according to DSM-IV entena and 25 controls (healthy siblings of cases), adding 14 cases and 11 controls. Results: 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 percent) in cases (40), compared with (2.8 percent) unaffected siblings (36), with an odds-ratio of 10.16. Conclusions: 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 ofADHD.
Subject(s)
Child , Humans , Attention Deficit Disorder with Hyperactivity/genetics , Dopamine Plasma Membrane Transport Proteins/genetics , Family , Polymorphism, Genetic/genetics , /genetics , Case-Control Studies , Diagnostic and Statistical Manual of Mental Disorders , Gene Frequency , Genetic Predisposition to Disease , Genotype , Minisatellite Repeats , Polymerase Chain Reaction , Risk FactorsABSTRACT
Background: Williams syndrome (WS) is a genetically based disorder caused by deletion of elastin and contiguous genes on chromosome 7q11.23. This syndrome is characterized by multiorganic involvement with dysmorphic facial features and a distinctive cognitive profile. It is an interesting model for elucidation of relationships between brain, cognition and genes. Patients have a visual-spatial cognition impaired with relative strengths in social and language abilities. Aim: To report clinical, cytogenetic, neurophysiological and neuroanatomic features in 44 patients referred as WS. Patients and methods: Forty four patients, aged 2 to 17 years, with the clinical diagnosis of Williams syndrome were studied with fluorescence in situ hybridization (FISH). In three cases, electrophysiological and neuroimaging studies were performed. Result: The deletion was confirmed in 23 patients. In three patients with neurophysiological studies, event related potentials suggested a cognitive difficulty in detecting and processing visual stimuli. Magnetic resonance imaging showed normal brain morphology. SPECT showed hypoperfusion of the right frontal lobe and bilateral anterior cingulum hyperperfusion. Conclusions: There are functional alterations in the brains of patients with Williams, which may be related to the cognitive deficits
Subject(s)
Humans , Male , Adolescent , Female , Child, Preschool , In Situ Hybridization, Fluorescence/methods , Williams Syndrome/genetics , Tomography, Emission-Computed, Single-Photon , Chromosome Deletion , Neurobehavioral Manifestations , Evoked Potentials , Cytogenetic Analysis , Williams Syndrome/diagnosis , Williams Syndrome/physiopathologyABSTRACT
Esta comunicación pretende mostrar un caso de Munchausen-por-poder que se presentó en un hospital de Santiago, planteando un importante desafío al equipo médico. El artículo intenta hacer una reflexión en torno a la problemática que generan estos casos que constituyen una forma de abuso físico muy elaborada y finamente perversa. Se realiza una definición y descripción de esta patología y se analiza en detalle el caso ocurrido. La mayor dificultad de este caso fue manterner el diagnóstico de Munchausen-por-poder vigente como una alternativa, aun cuando se planteó este diagnóstico desde el momento del ingreso. Por otra parte, los conflictos éticos y legales que esta situación produjo, expusieron a un niño pequeño a la posibilidad de quedar desprotegido e indefenso con alto riesgo vital