In the largest genetic analysis of Parkinson’s disease ever, now a total of 11 genetic variants have been discovered as related causes of the crippling disease which to date, has no cure. These variants were defined from a pool of 7.7 million potential culprits.

There are five major pathways in the brain connecting other brain areas with the basal ganglia. These are known as the motor, oculo-motor, associative, limbic and orbitofrontal circuits, with names indicating the main projection area of each circuit. All of them are affected in Parkinson’s disease (PD), and their disruption explains many of the symptoms of the disease since these circuits are involved in a wide variety of functions including movement, attention and learning. Until recently, environmental factors were thought to be wholly responsible for Parkinson’s disease.

This worldwide collaboration transpired between investigators in the UK, USA, Germany, France, The Netherlands and Iceland. The authors of this groundbreaking study state in an upcoming edition of The Lancet:

“This study provides evidence that common genetic variation plays an important part in the cause of Parkinson’s disease. We have confirmed a strong genetic component to Parkinson’s disease, which, until recently, was thought to be completely caused by environmental factors. The identification of additional common and rare risk variants for Parkinson’s disease will probably revise our estimate of the genetic component of disease upward.”

Parkinson’s disease is better understood than most other neurological disorders, in that its main symptoms are known to be caused by loss of a specific group of cells in a specific part of the brain. What is not known, for most cases, is the mechanism that causes those specific cells to be lost. There is little prospect of dramatic new PD treatments expected in a short time frame, but several lines of research are aimed at answering the critical questions. Currently active research directions include the search of new animal models of the disease, and studies of the potential usefulness of gene therapy, stem cells transplants and neuroprotective agents.

In late 1999, actor Michael J. Fox made the startling announcement that he had been battling Parkinson’s disease since 1991, and had even undergone brain surgery to alleviate tremors. Despite his incredible success and a showering of Emmy and Golden Globe awards, Fox announced in early 2000 that he would leave show business, to spend time with his family, and to concentrate on raising money and awareness for Parkinson’s disease. In May 2000, he launched the Michael J. Fox Foundation for Parkinson’s Research.

Dr Christine Klein and Dr Andreas Ziegler, University of Lübeck, Germany adds:

“The Consortium’s confirmation and discovery of potentially causal SNPs for the disease hold great promise for establishing causal hypotheses. This landmark study also serves another important purpose in that it provides a comprehensive stock-check on where we stand on our way towards clinical use of GWAS data in Parkinson’s disease.”

Source: The Lancet

Written By Sy Kraft, B.A.