Functional polymorphism of matrix metalloproteinase-9 (MMP9) gene is not associated with schizophrenia and with its deficit subtype

BackgroundThe deficit subtype of schizophrenia is hypothesized to constitute a pathophysiologically distinct subgroup of schizophrenia patients suffering from enduring, idiopathic negative symptoms and various neuropsychological deficits. Matrix metalloproteinases (MMPs) are extracellularly acting endopeptidases the substrates of which are matrix and adhesion molecules. Recently, MMP9 has been shown to be involved in various forms of synaptic plasticity, learning and memory consolidation. The primary aim of the present study was to evaluate associations between the functional MMP-9 −1562C/T gene polymorphism and the deficit and non-deficit subtypes of schizophrenia.MethodsThe study was conducted between 2009 and 2012. Deficit schizophrenia was diagnosed using the SDS. The sample consisted of 468 patients, Caucasians, of Polish descent with ICD 10 diagnosis of schizophrenia: 189 [51% males] were included in a non-deficit subgroup, 279 patients [53% males] were included in a deficit subgroup. The control group consisted of 532 subjects, Caucasians, of Polish descent [51% males]. MMP-9 −1562C/T gene polymorphism was genotyped using the fluorescence resonance energy transfer (FRET) method and the Light Cycler System 2.0.ResultsThe frequencies of genotypes and alleles did not differ between the schizophrenia patients and control group. The deficit and non-deficit patients did not differ in terms of the genotype and allele frequencies. No differences were found in genotype and allele frequencies between the deficit patients and the controls and between the non-deficit patients and the controls.ConclusionWe found no evidence for the association between the functional MMP-9 −1562C/T gene polymorphism and deficit/non-deficit subtypes of schizophrenia.