No association of GPNMB rs156429 polymorphism with Parkinson's disease, amyotrophic lateral sclerosis and multiple system atrophy in Chinese population

Background: The rs156429 polymorphism in the glycoprotein nonmetastatic melanoma protein B (GPNMB) gene was found to be associated with the risk for Parkinson disease (PD) in Caucasian population by genome-wide association studies (GWAS). Recently, encoded protein, GPNMB, was identified as a novel neuro-protective factor in amyotrophic lateral sclerosis (ALS). The overlapping of clinical manifestations and pathologic characteristics among PD, ALS, and multiple system atrophy (MSA) are observed. Object: This study aimed at investigating the possible associations of the polymorphism and the three neurodegenerative diseases: PD, ALS and MSA in a Chinese population. Methods: All of the subjects, including PD (n = 1096), sporadic ALS (SALS) (n=876) and MSA (n=356) patients, and 829 health controls (HCs) were included. All subjects were genotyped for this polymorphism using Sequenom iPLEX Assay technology. Results: No differences were found in the genotype distributions and minor allele frequency of GPNMB rs156429 between PD patients and HCs, between SALS patients and HCs, between MSA patients and HCs, and between subgroups of PD, ALS and MSA patients with regard to clinical features such as sex, age of onset, presence or absence of cognitive abnormality, depression and anxiety. Conclusion: Lack of association identified in our study suggests that it may be premature to conclude associations between GPNMB rsl 56429 and SALS, PD and MSA. More studies on such an association involving a larger number of participants are needed to confirm the present findings. (C) 2016 Elsevier Ireland Ltd. All rights reserved.