Schizophrenia Linked To Mutation In Serotonin Receptor
New research published in JAMA Psychiatry suggests doctors may have found a mutation in the gene for a serotonin receptor that plays a functional role in schizophrenia, including how patients respond to treatment. As reported by Michael Smith, correspondent for MedPage Today, the mutation in the gene for serotonin receptor 2a is a single nucleotide polymorphism called rs6314, which affects gene expression in the lab and cognitive abilities in patients. The gene also predicts how well schizophrenic patients will respond to being treated by olanzapine (Zyprexa), an atypical antipsychotic.
The researchers did however caution that the results “do not explain the whole of variation in the phenotypes investigated here, and they should be interpreted with consideration of the complexity of genetic and environmental loads acting on the function of the brain.” The mutation does appear to play a role in phenotypes associated with schizophrenia, but it is only a piece of the puzzle that creates a very complex mental illness.
Previous research has linked the mutation with hippocampal volume and activity, memory performance, and the way patients with schizophrenia respond to clozapine, noted lead researcher Alessandro Bertolino, MD, Ph.D, from Aldo Moro University in Bari, Italy. They also tested the cognitive effects of the genotype in over 300 patients without schizophrenia using three standard tests, which suggested a significant interaction between the genotype and working memory load. Those who carried to T allele did worse than those with two copies of the C variant normally found.
The result of the findings indicates that the carriers of the T allele, even if they show no signs of health problems, have “endophenotypes known to be related to genetic risk for schizophrenia,” the researchers concluded.