A multi-centre clinico-genetic analysis of the VPS35 gene in Parkinson disease indicates reduced penetrance for disease-associated variants

Abstract: Background Two recent studies identified a mutation (p.Asp620Asn) in the vacuolar protein sorting 35 gene as a cause for an autosomal dominant form of Parkinson disease. Although additional missense variants were described, their pathogenic role yet remains inconclusive. Methods and results We performed the largest multi-center study to ascertain the frequency and pathogenicity of the reported vacuolar protein sorting 35 gene variants in more than 15,000 individuals worldwide. p.Asp620Asn was detected in 5 familial and 2 sporadic PD cases and not in healthy controls, p.Leu774Met in 6 cases and 1 control, p.Gly51Ser in 3 cases and 2 controls. Overall analyses did not reveal any sig…

Myocardial 123metaiodobenzylguanidine uptake in genetic Parkinson's disease.

Myocardial (123)Metaiodobenzylguanidine (MIBG) enables the assessment of postganglionic sympathetic cardiac innervation. MIBG uptake is decreased in nearly all patients with Parkinson's disease (PD). Our objective was to evaluate MIBG uptake in patients with genetic PD. We investigated MIBG uptake in 14 patients with PD associated with mutations in different genes (Parkin, DJ-1, PINK], and leucine-rich repeat kinase 2 -LRRK2), in 15 patients with idiopathic PD, and 10 control subjects. The myocardial MIGB uptake was preserved in 3 of the 4 Parkin-associated Parkinsonisms, in I of the 2 patients with DJ-1 mutations, in 1 of the 2 brothers with PINK] mutations, in 3 of the 6 unrelated patient…

DCTN1 mutation analysis in Italian patients with PSP, MSA, and DLB

Abstract DCTN1 encodes the largest subunit of dynactin complex essential in the retrograde axonal transport and cytoplasmic transport of vesicles; mutations in DCTN1 have been reported predominantly in individuals with Perry syndrome and, recently, in patients with progressive supranuclear palsy. Our genetic screening of DCTN1 in 79 patients with progressive supranuclear palsy, 100 patients with multiple system atrophy, and 28 patients with dementia with Lewy bodies from Italy revealed only synonymous and intronic variants, suggesting that DCTN1 mutations do not have a key role in the development of atypical parkinsonism in the Italian population.

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

Recently, the LRP10 gene has been associated with Parkinson's disease (PD), Parkinson's disease with dementia (PDD), and dementia with Lewy bodies (DLB). The aim of the present study was to evaluate the presence of mutations of the LRP10 gene in patients with PD or DLB from Southern Italy. Sequencing analysis revealed only 2 missense and 3 synonymous variants in patients and control subjects and a rare variant p.L622F in a PD case. These results suggest that LRP10 mutations are not a frequent cause of PD and DLB in Southern Italy.

ANXA1 mutation analysis in Italian patients with early onset PD

: Recently, a novel pathogenic variant in Annexin A1 protein (c.4G > A, p.Ala2Thr) has been identified in an Iranian consanguineous family with autosomal recessive parkinsonism. The deficiencies of ANXA1 could lead to extracellular SNCA accumulation, defects in intracellular signaling pathways and synaptic plasticity causing parkinsonism. The aim of this study was to identify rare ANXA1 variants in 95 early-onset PD patients from South Italy. Sequencing analysis of ANXA1 gene revealed only 2 synonymous variants in PD patients (rs1050305, rs149033255). Therefore, we conclude that the recently published ANXA1 mutation is not a common cause of EOPD in Southern Italy.

Lack of association between ubiquitin carboxy-terminal hydrolase L1 gene polymorphism and PD.

In 1998, an IL93Met mutation in the ubiquitin carboxy-terminal hydrolase L1 ( UCH-L1 ) gene was identified in a German family affected by PD.1 Recently, others2-4⇓⇓ found that the S18Y polymorphism in exon 3 of UCH-L1 is associated with a low risk of PD. To verify these interesting results, we decided to design a case-control study on the S18Y polymorphism of the UCH-L1 gene using sporadic PD cases. In the meantime, as we were analyzing our samples, a case-control study5 on 142 patients with PD and 142 age- and sex-matched control subjects did not confirm the protective effect found by Maraganore et al.2 In view of these conflicting findings, we reasoned that our contribution may have some …

Identification of the novel D297fsX318 PINK1 mutation and phenotype variation in a family with early-onset Parkinson's disease

Herein we first describe a novel homozygous single nucleotide deletion in PINK1 exon 4 (889delG) which results in a loss of kinase domain on the PINK1 protein (D297fsX318). This mutation was identified in two brothers with early-onset Parkinson disease (EOPD) from a Sicilian consanguineous family. Of note, while one of the two patients developed mental deterioration and psychiatric problems, the other showed no cognitive decline. The present study supports the view that PINK1 is a pathogenic gene in some Italian families with EOPD and contributes to define the PINK1-associated phenotype. Herein we first describe a novel homozygous single nucleotide deletion in PINK1 exon 4 (889delG) which r…

Dentatorubral-pallidoluysian atrophy: haplotype of Asian origin in 2 Italian families.

The parkin gene is not a major susceptibility locus for typical late-onset Parkinson's disease

We investigated the parkin gene in 118 patients with typical Parkinson's disease (PD), i. e. in patients who had an onset of PD after the age of 45 years. The study group included 95 subjects with sporadic PD and 23 subjects from 18 families with autosomal recessive PD. No pathogenetic mutations in the parkin gene were detected either in familial or in sporadic patients. Our findings indicate that the parkin gene is not involved in the pathogenesis of classic late-onset PD.

Large-scale replication and heterogeneity in Parkinson disease genetic loci

Objective: Eleven genetic loci have reached genome-wide significance in a recent meta-analysis of genome-wide association studies in Parkinson disease (PD) based on populations of Caucasian descent. The extent to which these genetic effects are consistent across different populations is unknown. Methods: Investigators from the Genetic Epidemiology of Parkinson9s Disease Consortium were invited to participate in the study. A total of 11 SNPs were genotyped in 8,750 cases and 8,955 controls. Fixed as well as random effects models were used to provide the summary risk estimates for these variants. We evaluated between-study heterogeneity and heterogeneity between populations of different ances…

DJ-1 mutations and parkinsonism-dementia-amyotrophic lateral sclerosis complex.

Mutations in DJ-1 gene have been recently shown to cause autosomal recessive early-onset Parkinson’s disease (EOPD) in a large Dutch family and in a small consanguineous Italian family.1 Subsequent to this initial finding, several additional DJ-1 mutations were identified in subjects with EOPD.2–6 We describe a family from southern Italy with three brothers affected by a complex disorder characterized by early-onset parkinsonism-dementia-amyotrophic lateral sclerosis (EOPD-D-ALS). The analysis of the DJ-1 gene showed a novel homozygous mutation (E163K) in exon 7 and a novel homozygous mutation (g.168_185dup) in the promoter region of this gene in living affected subjects