Ausência de associação entre um polimorfismo do gene transportador de norepinefrina e esquizofrenia em uma amostra brasileira

Abstract

Post-mortem studies found increased levels of norepinephrine in the nucleus accumbens of patients with paranoid schizophrenia (SCZ). In chronic schizophrenic patients, the level of norepinephrine in the cerebrospinal fluid was increased. Medication-free relapsing patients also showed higher levels of norepinephrine and its metabolites in the cerebrospinal fluid. 1 The norepinephrine turnover was increased during acute psychotic episodes. 2 Early relapse of psychotic symptoms in patients with SCZ after neuroleptic (haloperidol) withdrawal was predicted by an increased noradrenergic activity during the treatment. 3 Since SCZ has a genetic compound on its etiology 4 and the noradrenergic system may be involved in the pathophysiology of the disorder, the norepinephrine transporter (NET) gene is a candidate for genetic studies on this disorder. NET is a 617amino acid protein and its gene is located on chromosome 16 (16q12), consisting of 14 exons (protein coding regions). We performed a study using a silent mutation, 1287 A/G, located in the exon 9 to verify its association with SCZ. This variant is unlikely to have any functional effect. We compared the allelic and genotypic distributions between 211 DSM-IV schizophrenic patients and 283 healthy controls.