Endemic parkinsonism associated with the rare haplotype of LRRK2 gene (P5.8-035)

Objective: The aim of the study was to investigate an co-occurence of rare variants in set of genes frequently associated with parkinsonism. Background: The increased prevalence of neurodegenerative parkinsonism with cognitive deterioration was detected in population of a small region of south-eastern Czech Republic (4,06% in the population over 65 years of age). Design/Methods: The molecular genetic examination was performed in 32 probands with parkinsonism and 20 asymptomatic controls from region under study. Coding sequences, exon/intron regions and 5’/3’UTR sequences of genes frequently associated with parkinsonism were tested with a MPS method using Ion Torrent technology and confirmed by Sanger sequencing. In total, 93 % of gene sequences were covered. Variants were filtered using parameter MAF Results: The joint occurence of 4 intron variants (rs11564187, rs36220738, rs200829235, rs3789329) and 1 exon variant (rs33995883) were identified in LRRK2 gene in 6 probands; none of these variants was found in controls. The impact of these 5 variants on the protein was verified using prediction tools. The exon variant was evaluated in the SIFT as benign, using PolyPhen-2 as pathogenic. For intron variants, the effect on alternative splicing of mRNA was evaluated. Using NetGene2, the variant rs200829235 resulted in a break of the splice site. Using Human Splicing finder 3.1, the variant rs200829235 resulted in activation of an exonic cryptic donor site and potential alteration of splicing, rs11564187 led to creation of a new donor site. Conclusions: Based on data of 1000 Genomes project, the frequency of the joint occurence of these variants in the population is almost exclusive, so we assume that these variants are in haplotype. Therefore, they may be associated with PD and may be one of the causes of parkinsonism in the investigated isolated region. Disclosure: Dr. Mensikova has nothing to disclose. Dr. Kolarikova has nothing to disclose. Dr. Vodicka has nothing to disclose. Dr. Vrtel has nothing to disclose. Dr. Bartonikova has nothing to disclose. Dr. Prochazka has nothing to disclose. Dr. Kanovsky has nothing to disclose.