No association of GSTP1 rs1695 polymorphism with amyotrophic lateral sclerosis: A case-control study in the Brazilian population

Amyotrophic Lateral Sclerosis (ALS) is a rare neurodegenerative disease that affects motor neurons and promotes progressive muscle atrophy. It has a multifactorial etiology, where environmental conditions playing a remarkable role through the increase of oxidative stress. Genetic polymorphisms in cell detoxification genes, such as Glutathione S-Transferase Pi 1 (GSTP1) can contribute to excessive oxidative stress, and therefore may be a risk factor to ALS. Thus, this study aimed to investigate the role of the GSTP1 rs1695 polymorphism in ALS susceptibility in different genetic inheritance models and evaluate the association of the genotypes with risk factors, clinical and demographic characteristics of ALS patients from the Brazilian central population. This case-control study was conducted with 101 patients with ALS and 101 healthy controls. GSTP1 rs1695 polymorphism genotyping was performed with Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP). The statistical analysis was carried out using the SPSS statistical package and SNPStats software. Analysis of genetic inheritance models was performed by logistic regression, which was used to determine the Odds Ratio. The results of this first study in the Brazilian population demonstrated that there was no risk association between the development of ALS and the GSTP1 rs1695 polymorphism in any genetic inheritance model (codominant, dominant, recessive, overdominant, and logarithmic); and that the polymorphic variants were not associated with the clinical and demographic characteristics of ALS patients. No association of the GSTP1 rs1695 polymorphism and ALS development in the Brazilian central population was found. These findings may be justified by the multifactorial character of the disease.