Association study between SMPD1 p.L302P and sporadic Parkinson's disease in ethnic Chinese population

The protein encoded by sphingomyelin phosphodiesterase 1, acid lysosomal (SMPD1) is a lysosomal acid sphingomyelinase. While there are increasing evidences to suggest that lysosomal enzyme defects and Parkinson's disease (PD) have strong associations, and recently, SMPD1 p.L302P (c.T911C, NM_000543) was found to be a risk factor for PD in Ashkenazi Jewish ancestry population, we try to investigate the possible association between SMPD1 p.L302P and sporadic PD in ethnic Chinese population.

455 sporadic PD and 476 health controls were included in our study. SMPD1 p.L302P (c.T911C) was genotyped by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and the results were confirmed by Sanger sequencing.

Our results showed that none of 455 sporadic PD and 476 health controls carried p.L302P. All of the 931 subjects' genotypes were wild type TT. Our data indicated that in an ethnic Chinese population, p.L302P did not appear to be enriched in sporadic PD, and p.L302P may not be a risk factor for Chinese sporadic PD. And combine our data with the results from previous studies, we found that all of the 2,268 participants of Chinese population carrying no p.L302P.

We could make a conclusion that p.L302P may not be common events for Chinese population. Sequencing of SMPD1 gene to find additional novel rare variants in the SMPD1 gene in diverse populations is needed.