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Peter Vieregge

Publications and source records attributed to Peter Vieregge.

15 recordsLinked to original sources
PubMed2006

MFN2 mutation distribution and genotype/phenotype correlation in Charcot-Marie-Tooth type 2.

Mutations in mitofusin 2 (MFN2) have been reported in Charcot-Marie-Tooth type 2 (CMT2) families. To study the distribution of mutations in MFN2 we screened 323 families and isolated patients with distinct CMT phenotypes. In 29 probands, we identified 22 distinct MFN2 mutations, and 14 of these mutations have not been reported before. All mutations were located in the cytoplasmic domains of the MFN2 protein. Patients presented with a classical but rather severe CMT phenotype, since 28% of them were wheelchair-dependent. Some had additional features as optic atrophy. Most patients had an early onset and severe disease status, whereas a smaller group experienced a later onset and milder disease course. Electrophysiological data showed in the majority of patients normal to slightly reduced nerve conduction velocities with often severely reduced amplitudes of the compound motor and sensory nerve action potentials. Examination of sural nerve specimens showed loss of large myelinated fibres and degenerative mitochondrial changes. In patients with a documented family history of CMT2 the frequency of MFN2 mutations was 33% indicating that MFN2 mutations are a major cause in this population.

Adolescent↗
PubMed2006

Influence of heterozygosity for parkin mutation on onset age in familial Parkinson disease: the GenePD study.

BACKGROUND: The PARK2 gene at 6q26 encodes parkin, whose inactivation is implicated in an early-onset autosomal recessive form of Parkinson disease (PD). OBJECTIVE: To evaluate the influence of heterozygosity for parkin mutation on onset age in a sample of families with at least 2 PD-affected members. DESIGN: Clinical and genetic study. SETTING: Twenty collaborative clinical sites. PATIENTS: Patients with familial PD collected in the GenePD study. Studied families were selected for (1) affected sibling pairs sharing 2 alleles identical by state at PARK2 (D6S305) or (2) 1 or more family members with onset age younger than 54 years, regardless of D6S305 status. At least 1 member from each of 183 families underwent comprehensive screening for deletion/insertion variants and point mutations in PARK2. MAIN OUTCOME MEASURES: Mutations in the parkin gene were screened by means of single-stranded conformation polymorphism and sequencing in all 12 coding exons and flanking intronic sequences for point mutations and duplex quantitative polymerase chain reaction in all exons for rearrangement, duplication, and deletion. RESULTS: Mutations were found in 23 families (12.6% of those screened). Among the mutation-positive families, 10 (43%) contained compound heterozygotes; 3 (13%), homozygotes; and 10 (43%), heterozygotes. The onset age in patients with parkin gene mutations ranged from 20 to 76 years. Patients with 1 parkin mutation had an 11.7-year age at onset than did patients with none (P = .04), and patients with 2 or more parkin mutations had a 13.2-year decrease in age at onset compared with patients with 1 mutation (P = .04). CONCLUSIONS: These data indicate that parkin mutations are not rare in multiply affected sibships, and that heterozygous mutation carrier status in PARK2 significantly influences age at onset of PD.

Adult↗
PubMed2006

Recurrent LRRK2 (Park8) mutations in early-onset Parkinson's disease.

Mutations in LRRK2 (leucine-rich repeat kinase 2) have been associated with autosomal dominant Parkinson's disease (PD) and cluster in several 3' exons of the gene. The majority of mutations have been detected in late-onset cases (age at onset >50 years). We screened 5 of the 51 exons of LRRK2 that previously have been reported to harbor mutations in 98 early-onset and 42 late-onset PD patients. We identified two mutations (c.4321C>T, c.6055G>A) in three early-onset patients. Screening of an additional 220 early-onset PD patients for these mutations revealed another mutation carrier. In conclusion, LRRK2 mutations need to be considered also in early-onset PD.

Adult↗
PubMed2005

Case-control study of multiple system atrophy.

The epidemiology of multiple system atrophy (MSA) is scarcely known, and risk factors have not been definitely identified. We investigated the effect of family history for neurodegenerative diseases and environmental factors on MSA risk in a multicentric case-control study. A total of 73 MSA patients (42 men, 31 women; age, 64.3 +/- 8.1 years; disease duration, 4.8 +/- 3.9 years), 146 hospital controls (84 men, 62 women; age, 64.9 +/- 8.4 years), and 73 population controls (42 men, 31 women; age, 63.7 +/- 8.9 years) matched for sex, age (+/-3 years), and province of residence were enrolled consecutively at seven neurological centers from 1 January 1994 to 31 July 1998. The following variables were investigated: family history of neurodegenerative diseases, education, smoking habits, hobbies, and occupational history. Occupational history of farming was significantly more frequent among MSA cases than controls (OR adj = 2.52; 95% CI, 1.25 to 5.07, MSA vs. hospital controls; OR adj = 4.53; 95% CI, 1.68 to12.2, MSA cases vs. population controls). A dose-response analysis for years of farming corroborated this association. We recently found that smoking is significantly less frequent among MSA cases than controls (Vanacore et al. [2000] Neurology 54:114-119). Here, we report that the effects of farming and smoking on MSA risk do not interact. Our results suggest that occupational history of farming is a risk factor for MSA. Smoking and farming seem to influence MSA risk independently. Further epidemiological studies might provide clues on the etiopathogenesis of MSA.

Aged↗
PubMed2004

Mutations in LRRK2 cause autosomal-dominant parkinsonism with pleomorphic pathology.

We have previously linked families with autosomal-dominant, late-onset parkinsonism to chromosome 12p11.2-q13.1 (PARK8). By high-resolution recombination mapping and candidate gene sequencing in 46 families, we have found six disease-segregating mutations (five missense and one putative splice site mutation) in a gene encoding a large, multifunctional protein, LRRK2 (leucine-rich repeat kinase 2). It belongs to the ROCO protein family and includes a protein kinase domain of the MAPKKK class and several other major functional domains. Within affected carriers of families A and D, six post mortem diagnoses reveal brainstem dopaminergic degeneration accompanied by strikingly diverse pathologies. These include abnormalities consistent with Lewy body Parkinson's disease, diffuse Lewy body disease, nigral degeneration without distinctive histopathology, and progressive supranuclear palsy-like pathology. Clinical diagnoses of Parkinsonism with dementia or amyotrophy or both, with their associated pathologies, are also noted. Hence, LRRK2 may be central to the pathogenesis of several major neurodegenerative disorders associated with parkinsonism.

Adult↗
PubMed2004

Distribution, type, and origin of Parkin mutations: review and case studies.

Early-onset Parkinson's disease (PD) has been associated with different mutations in the Parkin gene (PARK2). To study distribution and type of Parkin mutations, we carried out a comprehensive literature review that demonstrated two prominent types of mutations among 379 unrelated mutation carriers: exon rearrangements involving exon 3, 4, or both, and alterations in exons 2 and 7, suggesting mutational hot spots or founders. To elucidate the origin of 14 recurrent Parkin mutations in our samples, we carried out a detailed haplotype analysis at the PARK2 locus. Thirty-eight mutation-positive individuals, available family members, and 62 mutation-negative individuals were genotyped. We determined allele frequencies and linkage disequilibrium (LD) to evaluate the significance of shared haplotypes. We observed no LD between markers at PARK2. Our data support a common founder for the most frequent Parkin point mutation (924C>T; exon 7) and indicate a mutational hot spot as cause of a common small deletion (255/256delA; exon 2). Furthermore, the most frequent Parkin exon deletion (Ex4del) arose independently in 2 of our subjects. However, it also occurred as the result of a founder mutation in 2 cases that shared identical deletion break points. This study provides evidence for both mutational hot spots and founder mutations as a source of recurrent mutations in Parkin, regardless of the mutation type.

Adult↗
PubMed2002

The striatal dopaminergic deficit is dependent on the number of mutant alleles in a family with mutations in the parkin gene: evidence for enzymatic parkin function in humans.

Autosomal recessive parkinsonism associated with mutations in the parkin gene represents a monogenic form of hereditary parkinsonism. We performed [(18)F]6-fluorodopa (FDOPA) positron emission tomography as a measurement of the nigrostriatal dopaminergic system as well as extensive haplotype analysis of the PARK 2 gene locus in 14 subjects with parkin mutations. In parkin subjects, the reduction of striatal FDOPA uptake increased with the number of mutated alleles and was also slightly obvious in asymptomatic parkin gene carriers in the heterozygous state. The abnormal FDOPA uptake pattern in parkin patients did not significantly differ from that of sporadic Parkinson's disease. Our data are in agreement with an enzymatic dysfunction of the gene's translational product, which has been shown to promote protein degradation as an ubiquitin-protein ligase. Thus, parkinsonism in parkin gene carriers may be related to abnormal nigral protein accumulation in the presence of a suprathreshold enzyme dysfunction.

Adult↗
PubMed2002

PARK3 influences age at onset in Parkinson disease: a genome scan in the GenePD study.

Parkinson disease (PD) is a late-onset neurodegenerative disorder. The mean age at onset is 61 years, but the disease can range from juvenile cases to cases in the 8th or 9th decade of life. The parkin gene on chromosome 6q and loci on chromosome 1p35-36 and 1p36 are responsible for some cases of autosomal recessive early-onset parkinsonism, but they do not appear to influence susceptibility or variability of age at onset for idiopathic PD. We have performed a genomewide linkage analysis using variance-component methodology to identify genes influencing age at onset of PD in a population of affected relatives (mainly affected sibling pairs) participating in the GenePD study. Four chromosomal loci showed suggestive evidence of linkage: chromosome 2p (maximum multipoint LOD [MaxLOD] = 2.08), chromosome 9q (MaxLOD = 2.00), chromosome 20 (MaxLOD = 1.82), and chromosome 21 (MaxLOD = 2.21). The 2p and 9q locations that we report here have previously been reported as loci influencing PD affection status. Association between PD age at onset and allele 174 of marker D2S1394, located on 2p13, was observed in the GenePD sample (P=.02). This 174 allele is common to the PD haplotype observed in two families that show linkage to PARK3 and have autosomal dominant PD, which suggests that this allele may be in linkage disequilibrium with a mutation influencing PD susceptibility or age at onset of PD.

Adult↗
PubMed2002

Brain potential signs of slowed stimulus processing following cholecystokinin in Parkinson's disease.

RATIONALE: Cholecystokinin (CCK) is a neuropeptide which is colocalized with dopamine (DA) in neurons of the mesolimbic-frontocortical and nigrostriatal DA system. In animals CCK enhances DA activity in these systems. OBJECTIVES: The present study examined the effects of a single intranasal administration of CCK-8 on auditory brain potential (AEP) signs of cognitive processing and on motor performance in patients with Parkinson's disease (PD), known to originate from degeneration of DA neurons primarily in the nigrostriatal DA system. METHODS: Thirteen PD patients were examined after medication withdrawal, on two occasions after administration of placebo and 25 microg CCK-8, and compared with healthy controls matched for age and sex. AEPs were recorded while subjects performed an attention task (oddball paradigm). RESULTS: In the placebo condition, AEPs in the PD patients did not show marked alteration but were rather comparable to those in the controls. In healthy controls, CCK-8 enhanced the P3 complex ( P<0.05) and shortened latencies of the N2 and P3 components of the AEP evoked by task relevant target stimuli ( P<0.05). Contrary to expectations, in PD patients these AEP components were distinctly delayed after CCK-8 ( P<0.05). Motor performance was not changed by CCK-8 in PD patients or in controls. CONCLUSION: Data indicate a deleterious rather than beneficial effect of CCK on cognitive processing in PD patients that might result from a prevailing effect of the neuropeptide on transmitter systems (e.g. GABAergic) other than the DA system.

Aged↗
PubMed2002

Role of parkin mutations in 111 community-based patients with early-onset parkinsonism.

Early-onset parkinsonism is frequently reported in connection with mutations in the parkin gene. In this study, we present the results of extensive genetic screening for parkin mutations in 111 community-derived early-onset parkinsonism patients (age of onset <50 years) from Germany with an overall mutation rate of 9.0%. Gene dosage alterations represented 67% of the mutations found, underlining the importance of quantitative analyses of parkin. In summary, parkin mutations accounted for a low but significant percentage of early-onset parkinsonism patients in a community-derived sample.

Adult↗