GBA variants in REM sleep behavior disorder: a multicenter study

To study the role of GBA variants in the risk for isolated rapid-eye-movement (REM)-sleep behavior disorder (iRBD) and conversion to overt neurodegeneration

Comprehensive analysis of familial parkinsonism genes in rapid-eye-movement sleep behavior disorder

Background: There is only partial overlap in the genetic background of isolated rapid-eye-movement sleep behavior disorder (iRBD) and Parkinson's disease (PD). Objective: To examine the role of autosomal dominant and recessive PD or atypical parkinsonism genes in the risk of iRBD. Methods: Ten genes, comprising the recessive genes PRKN, DJ-1 (PARK7), PINK1, VPS13C, ATP13A2, FBXO7, and PLA2G6 and the dominant genes LRRK2, GCH1, and VPS35, were fully sequenced in 1039 iRBD patients and 1852 controls of European ancestry, followed by association tests. Results: We found no association between rare heterozygous variants in the tested genes and risk of iRBD. Several homozygous and compound heterozygous carriers were identified, yet there was no overrepresentation in iRBD patients versus controls. Conclusion: Our results do not support a major role for variants in these genes in the risk of iRBD. \ua9 2020 International Parkinson and Movement Disorder Society

Novel Associations of BST1 and LAMP3 with Rapid Eye Movement Sleep Behavior Disorder

Objective To examine the role of genes identified through genome-wide association studies (GWASs) of Parkinson disease (PD) in the risk of isolated REM sleep behavior disorder (iRBD). Methods We fully sequenced 25 genes previously identified in GWASs of PD in a total of 1,039 patients with iRBD and 1,852 controls. The role of rare heterozygous variants in these genes was examined with burden tests. The contribution of biallelic variants was further tested. To examine the potential effect of rare nonsynonymous BST1 variants on the protein structure, we performed in silico structural analysis. Finally, we examined the association of common variants using logistic regression adjusted for age and sex. Results We found an association between rare heterozygous nonsynonymous variants in BST1 and iRBD (p = 0.0003 at coverage >50 7 and 0.0004 at >30 7), driven mainly by 3 nonsynonymous variants (p.V85M, p.I101V, and p.V272M) found in 22 (1.2%) controls vs 2 (0.2%) patients. All 3 variants seem to be loss-of-function variantswith a potential effect on the protein structure and stability. Rare noncoding heterozygous variants in LAMP3 were also associated with iRBD (p = 0.0006 at >30 7).We found no association between rare heterozygous variants in the rest of genes and iRBD. Several carriers of biallelic variants were identified, yet there was no overrepresentation in iRBD. Conclusion Our results suggest that rare coding variants in BST1 and rare noncoding variants in LAMP3 are associated with iRBD. Additional studies are required to replicate these results and to examine whether loss of function of BST1 could be a therapeutic target