Views differ on genetic discoveries

The genetic revolution in the Parkinson's field has been fast, so fast that there is still disagreement on how important it really is.

Brain puzzle
Photo: Getty images

What science has discovered about genetic links to Parkinson's disease is so new that there is not yet consensus in the scientific community on how significant these findings actually are. It is hardly surprising that genetics researchers believe that their significance is great.

"When we look at patients in the Stockholm area, it is at least 30 per cent who say they have a relative who has had the disease, but I think the significance of genetics is even greater," says Andrea Carmine Belin.

One reason for this is that Parkinson's has a roughly equal spread all over the world, while its population lives in quite different environments. Andrea Carmine Belin says this suggests that environment is of lesser importance. And Lars Olson agrees.

Greatly overestimated

"Everything is much more hereditary than we previously realised. For a long time, environment has been greatly overestimated. It's almost been politically incorrect to talk about heredity, but we're now finding out how things really are," he says.

However, other Parkinson's researchers are much more cautious in their assessment of the importance of genetics.

"There are some variants of Parkinson's disease where the genetic component is very strong, but compared to schizophrenia, for example, the genetic link is much weaker in Parkinson's," says Thomas Perlmann, Professor of Molecular Developmental Biology at Karolinska Institutet's Department of Cell and Molecular Biology.

Small percentage

"It is still the case that only a very small percentage of all Parkinson's can be explained by genetics. It is essentially a multi-factorial disease," says Ernest Arenas, Professor of Molecular Neurobiology at Karolinska Institutet's Department of Medical Biochemistry and Biophysics.

The fact is that about ten per cent of all Parkinson's cases today can be explained by a direct genetic link. The remaining mutations found are seen as risk factors. But on the other hand, it is only around 15 years since the first evidence was presented of there even being a genetic cause behind Parkinson's disease, and much research remains before we gain a fully clear picture.

Text: Fredrik Hedlund. Published in Medicinsk Vetenskap 2/2013