High-Throughput Sequencing Haplotype Analysis Indicates in LRRK2 Gene a Potential Risk Factor for Endemic Parkinsonism in Southeastern Moravia, Czech Republic.

Parkinson's disease and parkinsonism are relatively common neurodegenerative disorders. This study aimed to assess potential genetic risk factors of haplotypes in genes associated with parkinsonism in a population in which endemic parkinsonism and atypical parkinsonism have recently been found. The genes ADH1C, EIF4G1, FBXO7, GBA, GIGYF2, HTRA2, LRRK2, MAPT, PARK2, PARK7, PINK1 PLA2G6, SNCA, UCHL1, and VPS35 were analyzed in 62 patients (P) and 69 age-matched controls from the researched area (C1). Variants were acquired by high-throughput sequencing using Ion Torrent workflow. As another set of controls, the whole genome sequencing data from 100 healthy non-related individuals from the Czech population were used (C2); the results were also compared with the Genome Project data (C3). We observed shared findings of four intron (rs11564187, rs36220738, rs200829235, and rs3789329) and one exon variant (rs33995883) in the LRRK2 gene in six patients. A comparison of the C1-C3 groups revealed significant differences in haplotype frequencies between ratio of 2.09 for C1, 1.65 for C2, and 6.3 for C3, and odds ratios of 13.15 for C1, 2.58 for C2, and 7.6 for C3 were estimated. The co-occurrence of five variants in the LRRK2 gene (very probably in haplotype) could be an important potential risk factor for the development of parkinsonism, even outside the recently described pedigrees in the researched area where endemic parkinsonism is present.

New endemic familial parkinsonism in south Moravia, Czech Republic and its genetical background.

An increased prevalence of familial neurodegenerative parkinsonism or cognitive deterioration was recently found in a small region of southeastern Moravia.The aim of the study was to assess the genetic background of this familial disease.Variants in the ADH1C, EIF4G1, FBXO7, GBA + GBAP1, GIGYF2, HTRA2, LRRK2, MAPT, PRKN, DJ-1, PINK1, PLA2G6, SNCA, UCHL1, VPS35 genes were examined in 12 clinically positive probands of the pedigree in which familial atypical neurodegenerative parkinsonism was identified in previous epidemiological studies. Libraries were sequenced by massive parallel sequencing (MPS) on the Personal Genome Machine (PGM; Ion Torrent). Data were analyzed using Torrent Suite and IonReporter software. All variants were then verified and confirmed by Sanger sequencing.We identified 31 rare heterozygous variants: 11 missense variants, 3 synonymous variants, 8 variants in the UTR region, and 9 intronic variants. Six variants (rs1801334, rs33995883, rs35507033, rs781737269, rs779760087, and rs63750072) were evaluated as pathogenic by at least one in-silico predictor.No single "founder" pathogenic variant associated with parkinsonism has been found in any of the probands from researched pedigree. It may rather be assumed that the familial occurrence of this disease is caused by the combined influence of several "small-effect" genetic variants that accumulate in the population with long-lasting inbreeding behavior.

Familial atypical parkinsonism with rare variant in VPS35 and FBXO7 genes: A case report.

BACKGROUND: A higher prevalence of parkinsonism was recently identified in southeastern Moravia (Czech Republic). Further research confirmed 3 large pedigrees with familial autosomal-dominant parkinsonism spanning 5 generations. METHODS: This case report concerns a patient belonging to one of these 3 pedigrees, in whom motor and oculomotor symptoms were accompanied by frontal-type dementia, who finally developed a clinical phenotype of progressive supranuclear palsy. Molecular genetic examinations were performed due to the positive family history. RESULTS: No previously described causal mutation was found. After filtering against common variants (minor allele frequency (MAF) < 0.01), 2 noncoding and 1 synonymous rare mutation potentially associable with parkinsonism were identified: GIGYF2-GRB10 Interacting GYF Protein 2, PARK11 (c.*2030G > A, rs115669549); VPS35 gene-vacuolar protein sorting 35, PARK17 (c.102 + 33G > A, rs192115886); and FBXO7-F-box only protein 7 gene, PARK15 (c.540A > G, rs41311141). CONCLUSION: As to the changes in the FBXO7 and VPS35 genes (despite phylogenetic conservation in primates), probably neither the FBXO7 nor the VPS35 variants will be direct causal mutations. Both described variants, and possibly the influence of their combination, could increase the risk of the disease.

Familial, autosomal-dominant neurodegenerative parkinsonism with cognitive deterioration spanning five generations in a genetically isolated population of south-eastern Moravia, Czech Republic.

BACKGROUND: An epidemiological study conducted over four years revealed increased prevalence of neurodegenerative parkinsonism in a small, isolated region (10 villages, with a combined population of 8664, with approx. 2927 over 50 years of age) of south-eastern Moravia, Czech Republic. The aim of this study was to obtain more detailed information on the medical history of the relatives of individuals with confirmed parkinsonism in an isolated rural population in south-eastern Moravia, Czech Republic. METHODS: We did detailed genealogical research on the families of all inhabitants with confirmed parkinsonism and compiled the pedigrees. These were modified on the basis of information from a consecutive door-to-door survey and local municipal and church registers. RESULTS: In the first stage, three large pedigrees with a familial occurrence of parkinsonism were found; two originated in one of the region's villages. In the second stage, these two pedigrees were combined into one large family tree. CONCLUSIONS: The high prevalence of parkinsonism in the researched area is caused by the familial aggregation of parkinsonism that was found in two large family trees. This is probably the result of the genetic isolation of the regional population due to the very low migration rate of its inhabitants to neighboring regions in the last two centuries.