12 agosto 2011

Scoperti 29 nuovi geni coinvolti nella Sclerosi Multipla (Nature 476, 214–219, 11 August 2011)

Nature Letter Multiple Sclerosis Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis è il titolo dello studio, pubblicato ieri su Nature, è il risultato delle ricerche condotte dai consorzi “International Multiple Sclerosis Genetics Consortium” e “Wellcome Trust Case Control Consortium”. I 250 coinvolti nelle ricerche, coordinate dalle Università di Oxford e Cambridge, hanno analizzato il Dna di 9.772 persone malate di Sclerosi Multipla e quello di 17.376 soggetti sani. Il risultato è di notevole importanza anche perché conferma che i meccanismi causali della Sclerosi Multipla sono in prevalenza immunologici. In altre parole la causa della malattia sarebbe riconducibile, come precedentemente ipotizzato, a significative alterazioni del sistema immunitario e a processi infiammatori a livello cerebrale.
La ricerca in questo campo registra una lunga catena di successi, e con velocità crescente: nel 1970 fu identificato il primo gene coinvolto nella Sclerosi Multipla, nel 2007 ne furono individuati 3 e negli ultimi tre anni ne sono stati scoperti 20, ora altri 29 e siamo quindi a quota 57 in totale.

Tra gli articoli citati nell'articolo compare anche il lavoro di Serena Sanna et al: "Variants within the immunoregulatory CBLB gene are associated with multiple sclerosis" pubblicato il 9 Maggio sulla rivista Nature Genetics.
CBLB: gene coinvolto nella sclerosi multipla. La conferma da uno studio (sardo) pubblicato su Nature Genetics


Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis
The International Multiple Sclerosis Genetics Consortium & The Wellcome Trust Case Control Consortium
Abstract
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability1. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals2, 3, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk4. Modestly powered genome-wide association studies (GWAS)5, 6, 7, 8, 9, 10 have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility11. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.

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