The relationship between obsessive-compulsive symptoms and PARKIN genotype: The CORE-PD study.

Background: Few studies have systematically investigated the association between PARKIN genotype and psychiatric co-morbidities of Parkison's disease (PD). PARKIN-associated PD is characterized by severe nigral dopaminergic neuronal loss, a finding that may have implications for behaviors rooted in dopaminergic circuits such as obsessive-compulsive symptoms (OCS).

Methods: The Schedule of Compulsions and Obsessions Patient Inventory (SCOPI) was administered to 104 patients with early-onset PD and 257 asymptomatic first-degree relatives.

Parkinson disease phenotype in Ashkenazi Jews with and without LRRK2 G2019S mutations.

The phenotype of Parkinson's disease (PD) in patients with and without leucine-rich repeat kinase 2 (LRRK2) G2019S mutations reportedly is similar; however, large, uniformly evaluated series are lacking. The objective of this study was to characterize the clinical phenotype of Ashkenazi Jewish (AJ) PD carriers of the LRRK2 G2019S mutation. We studied 553 AJ PD patients, including 65 patients who were previously reported, from three sites (two in New York and one in Tel-Aviv).

Cognitive and motor function in long-duration PARKIN-associated Parkinson disease.

Importance: Data on the long-term cognitive outcomes of patients with PARKIN-associated Parkinson disease (PD) are unknown but may be useful when counseling these patients.

Objective: Among patients with early-onset PD of long duration, we assessed cognitive and motor performances, comparing homozygotes and compound heterozygotes who carry 2 PARKIN mutations with noncarriers.

Design, Setting, And Participants: Cross-sectional study of 44 participants at 17 different movement disorder centers who were in the Consortium on Risk for Early-Onset PD study with a duration of PD greater than the median duration (>14 years): 4 homozygotes and 17 compound heterozygotes (hereafter referred to as carriers) and 23 noncarriers.

Neuropsychological Profile of Parkin Mutation Carriers with and without Parkinson Disease: The CORE-PD Study.

The cognitive profile of early onset Parkinson's disease (EOPD) has not been clearly defined. Mutations in the parkin gene are the most common genetic risk factor for EOPD and may offer information about the neuropsychological pattern of performance in both symptomatic and asymptomatic mutation carriers. EOPD probands and their first-degree relatives who did not have Parkinson's disease (PD) were genotyped for mutations in the parkin gene and administered a comprehensive neuropsychological battery.

Frequency of known mutations in early-onset Parkinson disease: implication for genetic counseling: the consortium on risk for early onset Parkinson disease study.

Objective: To assess the frequency and clinical characteristics of carriers of previously identified mutations in 6 genes associated with early-onset Parkinson disease (PD) and provide empirical data that can be used to inform genetic counseling.

Design: Cross-sectional observational study.

Setting: Thirteen movement disorders centers.

Predictors of parkin mutations in early-onset Parkinson disease: the consortium on risk for early-onset Parkinson disease study.

Background: Mutations in the parkin gene are the most common genetic cause of early-onset Parkinson disease (PD). Results from a multicenter study of patients with PD systematically sampled by age at onset have not been reported to date.

Objective: To determine risk factors associated with carrying parkin mutations.

Self-report of cognitive impairment and mini-mental state examination performance in PRKN, LRRK2, and GBA carriers with early onset Parkinson's disease.

While little is known about risk factors for cognitive impairment in early onset Parkinson disease (EOPD), postmortem studies have shown an association between dementia with Lewy bodies (DLB) and glucocerebrosidase (GBA) mutation. We compared Mini-Mental State Examination (MMSE) performance and self-reported cognitive impairment in 699 EOPD participants genotyped for mutations in parkin (PRKN), leucine-rich repeat kinase-2 (LRRK2), and GBA. Logistic regression was used to assess the association between reported cognitive impairment and MMSE score, as well as between GBA group membership and self-reported impairment and MMSE.

Motor phenotype of LRRK2 G2019S carriers in early-onset Parkinson disease.

Objective: To determine the motor phenotype of LRRK2 G2019S mutation carriers. LRRK2 mutation carriers were previously reported to manifest the tremor dominant motor phenotype, which has been associated with slower motor progression and less cognitive impairment compared with the postural instability and gait difficulty (PIGD) phenotype.

Design: Cross-sectional observational study.