Analysis of the LRP10 gene in patients with Parkinson’s disease and dementia with Lewy bodies from Southern Italy

Genetic analysis of the LRP10 gene in Chinese patients with Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by resting tremor, bradykinesia, muscle rigidity, and abnormal gait. The low-density lipoprotein receptor-related protein 10 (LRP10) was recently shown to be a causal gene for PD, and different ethnic cohorts have distinct frequencies and spectrum of LRP10 variants.

METHODS

We sequenced the full coding regions and exon-intron boundaries of LRP10 in 129 patients with sporadic Chinese PD to further investigate the connection of LRP10 with PD in a sample of Chinese patients.

RESULTS

In this study, we identified four potentially pathogenic mutations, including one novel mutation of p.Gly328Asp and three known mutations of p.Cys165Tyr, p.Arg230Trp, and p.Arg661His in four of the 129 Chinese patients with PD.

CONCLUSION

According to our study, the LRP10 gene may attribute to PD pathogenesis.

Calabria as a Genetic Isolate: A Model for the Study of Neurodegenerative Diseases

Although originally multi-ethnic in its structure, nowadays the Calabria region of southern Italy represents an area with low genetic heterogeneity and a high level of consanguinity that allows rare mutations to be maintained due to the founder effect. A complex research methodology—ranging from clinical activity to the genealogical reconstruction of families/populations across the centuries, the creation of databases, and molecular/genetic research—was modelled on the characteristics of the Calabrian population for more than three decades. This methodology allowed the identification of several novel genetic mutations or variants associated with neurodegenerative diseases. In addition, a higher prevalence of several hereditary neurodegenerative diseases has been reported in this population, such as Alzheimer’s disease, frontotemporal dementia, Parkinson’s disease, Niemann–Pick type C disease, spinocerebellar ataxia, Creutzfeldt–Jakob disease, and Gerstmann–Straussler–Scheinker disease. Here, we summarize and discuss the results of research data supporting the view that Calabria could be considered as a genetic isolate and could represent a model, a sort of outdoor laboratory—similar to very few places in the world—useful for the advancement of knowledge on neurodegenerative diseases.

Role of LRP10 in Parkinson's disease in a Taiwanese cohort

INTRODUCTION

Variants in the low-density lipoprotein receptor-related protein 10 (LRP10), linked to inherited forms of α-synucleinopathies, have been reported. Nine variants of LRP10 were identified in the first such report, and subsequent studies have identified possible pathogenic variants in patients with sporadic Parkinson's disease (PD). Few studies have investigated the role of LRP10 in PD. We sought to validate the role of this gene in Taiwanese patients with PD.

METHODS

In total, 1277 individuals were included in this study (669 had PD and 608 were controls). The entire LRP10 coding exons and exon-intron boundaries were sequenced in 103 probands with early-onset PD or familial PD. We then genotyped the newly identified variants from the 103 patients and previously reported potential pathogenic variants in our cohort. The frequencies of variants were analyzed.

RESULTS

Five new and possibly pathogenic variants were identified initially. In total, 14 potentially pathogenic variants (including nine previously reported and five newly identified variants) were analyzed thereafter. We did not find any significant associations between any variant and the risk of PD. However, c.1424+5delG was identified in a patient with sporadic PD who was diagnosed as having PD and dementia and who had prominent psychiatric symptoms.

CONCLUSION

Although we identified a patient with sporadic PD and dementia carrying a c.1424+5delG variant, our data did not provide sufficient evidence to support the role of LRP10 in PD in Taiwanese adults.

Screening of LRP10 mutations in Parkinson's disease patients from Italy

INTRODUCTION

Parkinson's disease (PD) belongs to a family of neurodegenerative diseases characterized by alpha-synuclein accumulation in neurons, whose etiopathogenesis remains largely uncovered. Recently, LRP10 has been associated with PD, Parkinson's disease Dementia (PDD) and Dementia with Lewy Bodies (DLB) by linkage analysis and positional cloning in an Italian family with late-onset PD. After the first characterization of a LRP10 pathogenic variant, other eight mutations have been detected in an international series of 660 probands with either a clinical or pathological diagnosis of PD, PDD or DLB. However, the results of following replication studies were inconclusive and the pathogenic role of LRP10 is still debated. The aim of this study is to sequence the LRP10 gene in an Italian cohort of clinically-diagnosed PD patients and to compare the frequency of the identified variants with the ones found in a large cohort of Italian exomes.

METHODS

A cohort of 664 PD patients was analyzed by targeted Next Generation Sequencing approach. Identified LRP10 variants were subsequently confirmed by Sanger sequencing and searched for in an in-house database including 3596 Italian exomes.

RESULTS

We identified three PD patients carrying a rare heterozygous, potentially pathogenic variant (p.R296C, p.R549Q, p.R661C). None of them was detected in 3596 Italian exomes. Two of them (p.R296C and p.R661C) have been previously reported in one sporadic PD and one definite Progressive supranuclear palsy patients respectively. All three carriers had late-onset PD responsive to levodopa, characterized by both motor and non-motor features, but no cognitive impairment.

CONCLUSION

We report three rare possibly-pathogenic LRP10 variants in PD patients from Italy. Further investigations are required to definitively establish their role in alpha-synucleinopathies.