Paolo Lamberti

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.

Pain as a nonmotor symptom of Parkinson disease: evidence from a case-control study

OBJECTIVE To determine whether pain is more frequent among people with Parkinson disease (PD) than among age-matched controls. DESIGN Case-control study. PATIENTS AND METHODS Logistic regression models taking into account type of pain, time between pain and PD onset, and possible confounders were used to compare 402 PD patients with 317 age-matched healthy control subjects. RESULTS The overall frequency of pain was significantly greater in PD patients than in controls (281 [69.9%] vs 199 [62.8%]; P = .04), mainly because the healthy control group lacked dystonic pain. Conversely, the frequency of nondystonic pain was similar among PD patients and controls (267 [66.4%] vs 199 [62.8%]; P = .28). Nevertheless, we observed a significant association between PD and nondystonic pain, beginning after the onset of parkinsonian symptoms (odds ratio, 2.1; 95% confidence interval, 1.4-2.9). Cramping and central neuropathic pain were more frequent among PD patients than controls. About one-quarter of patients who experienced pain reported pain onset before starting antiparkinsonian therapy. CONCLUSION These data support the hypothesis that pain begins at clinical onset of PD or thereafter as a nonmotor feature of PD.

The G6055A (G2019S) mutation in LRRK2 is frequent in both early and late onset Parkinson’s disease and originates from a common ancestor

Background: Mutations in the gene Leucine-Rich Repeat Kinase 2 (LRRK2) were recently identified as the cause of PARK8 linked autosomal dominant Parkinson’s disease. Objective: To study recurrent LRRK2 mutations in a large sample of patients from Italy, including early (<50 years) and late onset familial and sporadic Parkinson’s disease. Results: Among 629 probands, 13 (2.1%) were heterozygous carriers of the G2019S mutation. The mutation frequency was higher among familial (5.1%, 9/177) than among sporadic probands (0.9%, 4/452) (p<0.002), and highest among probands with one affected parent (8.7%, 6/69) (p<0.001). There was no difference in the frequency of the G2019S mutation in probands with early v late onset disease. Among 600 probands, one heterozygous R1441C but no R1441G or Y1699C mutations were detected. None of the four mutations was found in Italian controls. Haplotype analysis in families from five countries suggested that the G2019S mutation originated from a single ancient founder. The G2019S mutation was associated with the classical Parkinson’s disease phenotype and a broad range of onset age (34 to 73 years). Conclusions: G2019S is the most common genetic determinant of Parkinson’s disease identified so far. It is especially frequent among cases with familial Parkinson’s disease of both early and late onset, but less common among sporadic cases. These findings have important implications for diagnosis and genetic counselling in Parkinson’s disease.

Incidence of amyotrophic lateral sclerosis in southern Italy: a population based study

Background: While the incidence of amyotrophic lateral sclerosis (ALS) is similar across the world (range, 1.0 to 2.5/100 000), a latitude gradient from north to south has been observed. Objective: To determine the incidence of ALS in Puglia, a region of south eastern Italy, and to test the latitude gradient hypothesis comparing the present study with findings in studies conducted with the same design in a northern latitude. Methods: Puglia (4 086 613 residents in 2001) is the site of a multicentre-multisource prospective population based registry established in 1997. All incident ALS cases during the period 1998–99 were enrolled and followed up. Cases were classified using the first and the revised El Escorial criteria. Results: During the study period 130 cases were enrolled. The annual crude incidence for ALS in Puglia for the two year period 1998–99 was 1.6/100 000 (95% confidence interval, 1.3 to 1.9). The incidence was higher for men (incidence rate (IR) = 2.1 (1.7 to 2.7) than for women (IR = 1.2 (0.9 to 1.5)) in all age groups, with a male to female ratio of 1.6. For both men and women, the incidence increased through age 75 and declined rapidly afterwards. The mean annual incidence adjusted by age and sex to the 2001 Italian population was 1.7/100 000 (1.4 to 2.0). Conclusions: ALS incidence is within a narrow range across countries, with a peak between 65 and 75 years and a higher incidence in men. A north to south latitude gradient of ALS incidence is not supported by the results of cohort studies.

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.

Freezing Gait in Parkinson's Disease

Freezing is a well-known problem in Parkinsons disease (PD) and is characterized by an abrupt difficulty in starting or continuing rhythmic and repetitive movements. We utilized a questionnaire in order to assess the occurrence of the freezing gait phenomenon (FG) in a population of 100 consecutive PD patients. Our PD population included 70 males and 30 females, with a mean age of 61.1 +/- 9.1 years. Mean duration of PD was 6.5 +/- 4.0 years. 92/100 patients were under L-Dopa treatment. The FG phenomenon occurred in 60% of patients. It appeared on average 4.8 years after the beginning of PD; in 16% of the cases it was evident before starting L-Dopa treatment. FG was more frequent among female patients. There was no significant correlation between the occurrence of FG and the age of the patients; on the other hand, a significant correlation was found with the duration of the disease (p < 0.001). FG occurred more frequently in the subgroup of patients with the akinetic form (odds ratio: 3.05); whilst an opposite tendency was evident in the subgroup with the tremor predominant form (odds ratio: 0.29).

Analysis of survival and prognostic factors in amyotrophic lateral sclerosis: a population based study.

Objective: To measure survivorship and predictors of prognosis of amyotrophic lateral sclerosis (ALS). Methods: Incident cases, diagnosed in the 1998–1999 period and classified according to the El Escorial criteria, were enrolled from a prospective population based registry established in Puglia, Southern Italy, with a reference population of 4 025 329. Cases were followed up until death or 30 June 2004. Results: We identified 130 incident cases of ALS while four were lost to follow-up. Median survival was 28 months from first symptoms and 16 months from diagnosis, while cumulative survivorship at 4 years was approximately 30%. Advanced age (>75 years: hazard ratio (HR) 7.5; 95% CI 1.9 to 29.6; p = 0.004) and bulbar or generalised (HR 1.8; 95% CI 1.1 to 3.0; p = 0.01) onset of symptoms were independent predictors of adverse survival. After stratifying patients according to site of first symptoms, age was a predictor of death among spinal (HR for patients aged >75 years compared with patients aged 45 years or less: HR 11; 95% CI 1.5 to 78.5; p = 0.01) but not among bulbar ALS (HR 4.5; 95% CI 0.4 to 46.5; p = 0.2). Among spinal onset cases, cases with predominant upper motoneuronal (UMN) involvement presented with a borderline significant better survivorship (HR 0.5; 95% CI 0.2 to 1.3; p = 0.1) Conclusions: Bulbar signs and advanced age among subjects with spinal onset were indicators of poor prognosis while El Escorial category at entry did not predict survival. Among subjects with spinal onset of the disease, a trend for a better survivorship of subjects with UMN signs was noted.

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.

Effects of levodopa and COMT inhibitors on plasma homocysteine in Parkinson's disease patients

Homocysteine (Hcy) is a risk factor for vascular diseases, cognitive impairment, and dementia. Elevated plasma concentrations of Hcy have been found recently in Parkinsons disease (PD) patients treated with levodopa, suggesting that levodopa is a cause of hyperhomocysteinemia (HHcy). The mechanism underlying HHcy in PD is the O‐methylation of levodopa catalyzed by catechol‐O‐methyltransferase (COMT) that produces S‐adenosylhomocysteine, which is hydrolyzed rapidly to Hcy. COMT inhibitors (COMT‐I) are used currently in the treatment of PD; however, no study has assessed the effects of COMT‐I administration on Hcy concentrations in PD patients. We compared plasma levels of Hcy, B12, and folate in 26 PD patients treated with levodopa, 20 PD patients treated with levodopa + COMT‐I, and 32 controls. No significant differences were found in vitamin B12 levels, whereas folate concentrations were significantly lower in the levodopa‐treated group. Plasma Hcy was increased significantly in the two groups of PD patients and was significantly lower in the group treated with levodopa + COMT‐I. Statistical analysis showed that the difference in mean Hcy levels observed among PD patients was related to the addition of COMT‐I, rather than to folate concentrations. We conclude that levodopa treatment increases plasma Hcy and the addition of COMT‐I effectively reduces HHcy.

Fibromyalgia Comorbidity in Primary Headaches

Fibromyalgia syndrome (FMS) is a chronic pain condition of unknown aetiology characterized by diffuse pain and tenderness at tender points. The aim of the study was to assess the prevalence and clinical features of FMS in the different forms of primary headaches, in a tertiary headache centre. Primary headache patients (n = 217) were selected and submitted to the Total Tenderness Score, anxiety and depression scales, Migraine Disability Assessment, allodynia questionnaire, Short Form 36 Health Survey and the Medical Outcomes Study-Sleep Scale. In patients with FMS, the Multidimensional Assessment of Fatigue, the Pain Visual Analog Scale, the Manual Tender Point Survey and the Fibromyalgia Impact Questionnaire were employed. FMS was present in 36.4% of patients and prevailed significantly in tension-type headache and in patients with higher headache frequency. Headache frequency, pericranial muscle tenderness, anxiety and sleep inadequacy were especially associated with FMS comorbidity. In the FMS patients, fatigue and pain at tender points were significantly correlated with headache frequency. FMS seems increasingly prevalent with increased headache frequency, for the facilitation of central sensitization phenomena favoured by anxiety and sleep disturbances.