Roberto Marconi

ATP13A2 missense mutations in juvenile parkinsonism and young onset Parkinson disease

Objective: To assess the prevalence, nature, and associated phenotypes of ATP13A2 gene mutations among patients with juvenile parkinsonism (onset <21 years) or young onset (between 21 and 40 years) Parkinson disease (YOPD). Methods: We studied 46 patients, mostly from Italy or Brazil, including 11 with juvenile parkinsonism and 35 with YOPD. Thirty-three cases were sporadic and 13 had positive family history compatible with autosomal recessive inheritance. Forty-two had only parkinsonian signs, while four (all juvenile-onset) had multisystemic involvement. The whole ATP13A2 coding region (29 exons) and exon-intron boundaries were sequenced from genomic DNA. Results: A novel homozygous missense mutation (Gly504Arg) was identified in one sporadic case from Brazil with juvenile parkinsonism. This patient had symptoms onset at age 12, levodopa-responsive severe akinetic-rigid parkinsonism, levodopa-induced motor fluctuations and dyskinesias, severe visual hallucinations, and supranuclear vertical gaze paresis, but no pyramidal deficit nor dementia. Brain CT scan showed moderate diffuse atrophy. Furthermore, two Italian cases with YOPD without atypical features carried a novel missense mutation (Thr12Met, Gly533Arg) in single heterozygous state. Conclusions: We confirm that ATP13A2 homozygous mutations are associated with human parkinsonism, and expand the associated genotypic and clinical spectrum, by describing a homozygous missense mutation in this gene in a patient with a phenotype milder than that initially associated with ATP13A2 mutations (Kufor-Rakeb syndrome). Our data also suggest that ATP13A2 single heterozygous mutations might be etiologically relevant for patients with YOPD and further studies of this gene in Parkinson disease are warranted.

Pramipexole versus sertraline in the treatment of depression in Parkinson's disease: a national multicenter parallel-group randomized study.

In addition to treating the motor symptoms of Parkinson’s disease, the dopamine agonist pramipexole has shown an antidepressant effect. The trials, however, included patients with motor complications, raising the question of whether the antidepressant benefit represented only a treatment–related motor improvement. To address this issue, we have conducted a 14–week randomized trial comparing pramipexole with an established antidepressant in patients without motor complications. At seven Italian centers, 67 Parkinsonian outpatients with major depression but no history of motor fluctuations and/or dyskinesia received open–label pramipexole (at 1.5 to 4.5 mg/day) or sertraline (at 50 mg/day). In both groups, the Hamilton Depression Rating Scale (HAM–D) score decreased throughout 12 weeks of treatment, but in the pramipexole group the proportion of patients who recovered, as defined by a final HAM–D score ≤ 8,was significantly higher, at 60.6% versus 27.3% (p = 0.006). Patients’ self–ratings improved in both groups. All adverse events were mild or moderate, but five patients (14.7%) withdrew from the sertraline group. Despite the absence of motor complications, the pramipexole recipients showed improvement on the Unified Parkinson’s Disease Rating Scale (UPDRS) motor subscore. We conclude that dopamine agonists may be an alternative to antidepressants in Parkinson’s disease.

Quetiapine and clozapine in parkinsonian patients with dopaminergic psychosis.

ObjectiveThis study aimed to compare the efficacy and safety of quetiapine and clozapine in parkinsonian patients with dopaminergic psychosis in a randomized, open-label, blinded-rater, parallel group trial. MethodsForty-five patients with Parkinson disease (PD) and psychosis induced by antiparkinsonian drugs were randomly assigned to receive either quetiapine or clozapine. The duration of the trial was 12 weeks. Forty patients, 20 in each treatment group, completed the study. The final dose of quetiapine (mean ± SD) was 91 ± 47 mg/d and that of clozapine 26 ± 12 mg/d. The severity of psychosis was assessed using the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression Scale–Severity Subscale (CGI-S). The Unified Parkinson’s Disease Rating Scale (UPDRS) III was used to assess motor conditions during the study period. The Abnormal Involuntary Movement Scale (AIMS) was performed to evaluate dyskinesias. ResultsForty patients, 20 on clozapine and 20 on quetiapine, completed the study. The psychopathologic state improved significantly (P < 0.001) from baseline in both treatment groups. No differences were found between clozapine and quetiapine at any assessment time. Motor conditions remained unchanged after clozapine and quetiapine. Dyskinesias decreased significantly (P < 0.05) in both groups. Side effects were mild, generally transient, and well tolerated. ConclusionsQuetiapine and clozapine appear equally efficacious for treatment of dopaminergic psychosis in patients with PD.

Comprehensive analysis of the LRRK2 gene in sixty families with Parkinson's disease

Mutations in the gene leucine-rich repeat kinase 2 (LRRK2) have been recently identified in families with Parkinsons disease (PD). However, the prevalence and nature of LRRK2 mutations, the polymorphism content of the gene, and the associated phenotypes remain poorly understood. We performed a comprehensive study of this gene in a large sample of families with Parkinsons disease compatible with autosomal dominant inheritance (ADPD). The full-length open reading frame and splice sites of the LRRK2 gene (51 exons) were studied by genomic sequencing in 60 probands with ADPD (83% Italian). Pathogenic mutations were identified in six probands (10%): the heterozygous p.G2019S mutation in four (6.6%), and the heterozygous p.R1441C mutation in two (3.4%) probands. A further proband carried the heterozygous p.I1371 V mutation, for which a pathogenic role could not be established with certainty. In total, 13 novel disease-unrelated variants and three intronic changes of uncertain significance were also characterized. The phenotype associated with LRRK2 pathogenic mutations is the one of typical PD, but with a broad range of onset ages (mean 55.2, range 38–68 years) and, in some cases, slow disease progression. On the basis of the comprehensive study in a large sample, we conclude that pathogenic LRRK2 mutations are frequent in ADPD, and they cluster in the C-terminal half of the encoded protein. These data have implications both for understanding the molecular mechanisms of PD, and for directing the genetic screening in clinical practice.

A study of five candidate genes in Parkinson’s disease and related neurodegenerative disorders

OBJECTIVE To determine whether reported genetic association of polymorphisms in the CYP2D6, CYP1A1, N-acetyltransferase 2 (NAT2), DAT1, and glutathione s-transferase M1 (GSTM1) genes with PD were evident in a population of 176 unrelated patients with sporadic PD and to extend these findings to other disease groups (familial PD [n = 30], ALS [n = 50], multiple system atrophy [n = 38], progressive supranuclear palsy [n = 35], and AD [n = 23]). METHODS A combination of allele-specific PCR and analysis of restriction fragment length polymorphisms were performed. RESULTS We genotyped 1,131 individuals. After matching each patient with a control subject by age, sex, ethnicity, and geographic origin, there was no association of any allele/genotype with any of the six disease groups. There was an increased frequency of NAT2 slow acetylators in the ALS group compared with controls (70% versus 50%; OR 2.33 [95% CI, 1.03 to 5.30]), but this was not significant after adjusting for multiple testing. CONCLUSIONS This is one of the most extensive candidate gene studies performed in PD and the first time that some of these loci have been studied in multiple system atrophy and progressive supranuclear palsy. In contrast with previous studies, we found no role for these polymorphisms in the etiology of PD, ALS, multiple system atrophy, progressive supranuclear palsy, or AD.

Prevalence of hereditary ataxias and spastic paraplegias in Molise, a region of Italy.

SummaryAn epidemiological survey of hereditary ataxias and paraplegias was conducted in Molise, a region of Italy (335, 211 inhabitants on 1 January 1989). Total prevalence was 7.5 x 10−5 inhabitants (95% confidence limits 4.8–11.1). There were 7 patients with Friedreichs disease, 5 with early onset cerebellar ataxia with retained tendon reflexes, 4 with ataxia-telangiectasia, 9 with hereditary spastic paraplegias (2 autosomal dominant and 7 autosomal recessive cases). There was no patient with autosomal dominant cerebellar ataxia.

Genetic data and natural history of Friedreich's disease: a study of 80 Italian patients

SummaryThe clinical and genetic features of 80 patients with Friedreichs disease from 64 families are described. Diagnostic criteria were: no evidence of dominant inheritance, onset by the age of 20 years, progressive unremitting ataxia of limbs and gait, and absence of knee and ankle jerks. Furthermore, at least one of the following accessory signs was present: dysarthria, extensor plantar response and echocardiographic evidence of hypertrophic cardiomyopathy. Two peaks of onset age were evident at 6–9 and 12–15 years. Analysis of intrafamily variation of onset age and absence of clustering of cardiomyopathy and diabetes did not suggest genetic heterogeneity. Peripheral nerve impairment was an early finding and showed slight further progression, whereas involvement of the cerebellar and corticospinal pathways appeared later and mainly accounted for the progressive worsening of the disease.

Direct genetic evidence for involvement of tau in progressive supranuclear palsy

Objective: To confirm whether a dinucleotide repeat sequence in an intron of the microtubule-associated protein tau is associated with progressive supranuclear palsy (PSP) in an independent study population and to establish an improved methodology for allelotyping. Background: It has recently been reported that a genetic variant of tau, known as the A0 allele, was represented excessively in PSP patients when compared with control subjects. Methods: In a multicenter study, the authors examined the allelic distribution of this dinucleotide repeat marker in a set of clinically ascertained PSP patients (n = 30), multiple system atrophy (MSA) patients (n = 35), and matched control subjects (n = 70). Individuals were allelotyped using automated analysis of fluorescently labeled PCR products. Results: The A0 allele was significantly overrepresented in the PSP patients (93.3% versus 76.4%; p = 0.0067; odds ratio [OR] = 4.33; 95% confidence interval [CI], 1.36 to 13.60), but not in the MSA patients. Likewise, A0 homozygotes were overrepresented in the PSP group (86.7% versus 61.1%; p = 0.02; OR = 4.14; 95% CI, 1.19 to 14.48) compared with control subjects. Conclusions: The findings of this study, which is the largest to date, support those of a previous investigation that used pathologically confirmed PSP patients. These data provide additional strong evidence that genetic variation at or near the tau gene plays an important role in the pathogenesis of PSP.

Smoking habits in multiple system atrophy and progressive supranuclear palsy

Objective: To evaluate smoking habits in patients with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) in a multicenter case–control study to determine whether these two forms of atypical parkinsonism share the inverse association with smoking previously found in PD. Background: No epidemiologic studies have been performed on smoking habits in MSA. A previous investigation in PSP revealed no differences in smoking habits between patients and hospital control subjects. Methods: Seventy-six MSA patients, 55 PSP patients, 140 PD patients, and 134 healthy control subjects were enrolled consecutively at seven neurologic clinics from January 1, 1994, to July 31, 1998. Detailed information on smoking habits was obtained using a structured questionnaire. Results: The comparison between frequencies of never-smokers versus ever-smokers (ex-smokers/current smokers; adjusted odds ratio [ORadj], 0.56; 95% CI, 0.29 to 1.06) and a dose–response analysis for never-smokers, moderate smokers (ORadj, 0.64; 95% CI, 0.31 to 1.32), and heavy smokers (ORadj, 0.47; 95% CI, 0.21 to 1.05) suggest that MSA patients smoke less than population control subjects. By contrast, the comparison of frequencies of never-smokers versus ever-smokers (ORadj, 0.91; 95% CI, 0.42 to 1.98) and a dose–response analysis for never-smokers, moderate smokers (ORadj, 0.68; 95% CI, 0.27 to 1.69), and heavy smokers (ORadj, 1.24; CI 95%, 0.51 to 3.06) revealed no differences in smoking habits between PSP patients and population control subjects. Conclusions: The fact that the inverse association with smoking found previously in PD is shared by multiple system atrophy but not by progressive supranuclear palsy lends epidemiologic support to the notion that different smoking habits are associated with different groups of neurodegenerative disease.

Novel parkin mutations detected in patients with early-onset Parkinson's disease

A multiethnic series of patients with early‐onset Parkinsons disease (EOP) was studied to assess the frequency and nature of parkin/PARK2 gene mutations and to investigate phenotype–genotype relationships. Forty‐six EOP probands with an onset age of <45 years, and 14 affected relatives were ascertained from Italy, Brazil, Cuba, and Turkey. The genetic screening included direct sequencing and exon dosage using a new, cost‐effective, real‐time polymerase chain reaction method. Mutations were found in 33% of the indexes overall, and in 53% of those with family history compatible with autosomal recessive inheritance. Fifteen parkin alterations (10 exon deletions and five point mutations) were identified, including four novel mutations: Arg402Cys, Cys418Arg, IVS11‐3C>G, and exon 8‐9‐10 deletion. Homozygous mutations, two heterozygous mutations, and a single heterozygous mutation were found in 8, 6, and 1 patient, respectively. Heterozygous exon deletions represented 28% of the mutant alleles. The patients with parkin mutations showed significantly earlier onset, longer disease duration, more frequently symmetric onset, and slower disease progression than the patients without mutations, in agreement with previous studies. This study confirms the frequent involvement of parkin and the importance of genetic testing in the diagnostic work‐up of EOP.