A novel technique that speeds up the examination of the genome (genetic make-up) of people has recently become available: before analyzing the sequence of nucleic acids of DNA (the letters of the genetic code) it identifies the Exome i.e. the part of DNA which is actually used to make proteins that become the building blocks of our body. This increases the probability of finding important mutations of genes (the functional units that code one or more proteins)
A group of international researchers, using exome sequencing to analyze the DNA of a few rare families with hereditary Parkinson’s disease (PD), have found a new gene, called VPS35, which is involved in PD. The mutation was sought in 4326 patients and 3309 control subjects without the disease: mutations of the gene were found in a few families with hereditary PD and in none of the healthy controls.
The VPS gene is dominant (it is sufficient to have one mutated copy of the gene to develop the disease), but its penetrance is incomplete (not all the people with this mutation develop the disease).
The gene is involved in old protein recycling i.e. in their transport in endosomes to the Golgi apparatus, which can be considered to be a storehouse of the cell. This discovery gives further credence to the theory that PD is due to a problem connected to old protein disposal]]>
Researchers of Louisiana University have presented data that suggest that Helicobacter pylori may have a role in the development of Parkinson’s disease at the meeting of the American Society of Microbiology. This bacterium occurs in the stomach of about half of the general population and has proved to be responsible for gastric and duodenal ulcers.
Within the context of an international research project, researchers analyzed the genome (genetic make-up) of more than 2000 patients suffering from a severe and rare form of parkinsonism, called Progressive Supranuclear Palsy (PSP). The results were compared with those obtained in 7000 control subjects without the disease. The analysis was carried out in two phases, starting from an initial sample of 1114 subjects who had died, in whom the diagnosis was certain, based on the outcome of their autopsy.]]>
Dr Vania Broccoli, Director of the Stem Cell and Neurogenesis Unit of San Raffaele Institute in Milan, Italy, together with his team of researchers, has developed a new method based on genetic engineering, which enables the transformation of skin cells (fibroblasts) into dopaminergic nervous cells (neurons) – the ones that patients with Parkinson’s disease lack. The method consists in the genetic reprogramming of the cell by inserting three genes (Mash1, Nurr1 e Lmx1a), which trigger the transformation into induced dopaminergic neurons (iDA).
The participants to the meeting for the relaunch of the World Parkinson Disease Association held in Buenos Aires included the President of the Grigioni Foundation for Parkinson's disease in Italy and the Presidents of all the Associations of patients with Parkinson’s disease in South America.
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Brain images of 44 patients with Parkinson’s disease, out of whom 17 had a history of repeated falls, and 15 health subjects were obtained by PET techniques using markers of dopaminerigc and cholinergic activity. Cholinergic activity was significantly lower in the cerebral cortex of patients vs subjects, especially in the patients with a history of repeated falls (patients who had fallen -12.3%, patients who had not -6.6%), whereas there were no differences between the patients who had fallen and those who had not in terms of dopaminergic activity. A 11.8% reduction in cholinergic activity in the thalamus was recorded only in the patients who had fallen.
Source: Bohnen N et al Neurology 2009; 17: 1670-1676]]>
Danish researchers analyzed the data related to dihydropyridine calcium-antagonists (such as nifedipine, felodipine, nicardipine) in the Danish national healthcare database, comparing 1931 subjects with Parkinson’s disease to 9651 subjects of same age and gender without the disease. They established that the risk of developing Parkinson’s disease was 27% lower in subjects on treatment with dihydropyridine calcium-antagonists, independently of dosage or duration of treatment.
Source: Ritz B et al Ann Neurol online December 2009]]>
1167 patients with Parkinson’s disease in South Corea were administered the Minnesota questionnaire to detect abnormal compulsions. 10% had abnormal compulsions, especially punding (tidying, cleaning and cataloging objects without any purpose) (4.2%), eating (3.4%), sexual behaviors (2.8%), shopping (2.5%) and gambling (1.3%). All these abnormal behaviors were related to the dose of dopamine agonist taken, except punding, which was related to the dose of levodopa, and eating, which was not related to the dose of any drug.
Source: Lee JY et al Parkinsonism Relat Disord online 15 December 2009]]>
American researchers analyzed the data related to 107,598 patients with Parkinson’s disease, included in clinical trials to establish their risk of developing a malignancy. They found that such risk was 27% lower vs controls without the disease. The reduction in risk increased up to 31% when skin cancer was excluded and regarded both smoking related (-39%) and non smoking related cancers (-24%).
Source: Bajaj A et al Cancer causes control online 7 January 2010]]>
Researchers working at the University of Basel conducted a retrospective study on a large number of subjects using the research database of UK GPs (UK General Practice Research Database). They compared the diagnoses of cancer between the patients diagnosed with Parkinson’s disease between 1994 and 2005 and a similar sample of subjects who did not have the disease. The risk of cancer was 23% lower in patients with Parkinson’s disease. In particular, the risk of a malignant tumor related to smoking, such as lung or bladder carcinoma, was 53% lower and the risk of hematological malignancy was 68% lower. The only exception was melanoma.
Source: Becker C et al Parkinsonism Relat Disord online 27 november 2009]]>