Gene clue to early onset Parkinson's disease

A study has shown that a gene mutation may be responsible for people developing Parkinson's disease before the age of 50. The results of the study, which was supported by grants from the US National Institutes of Health and the Parkinson's Disease Foundation, were published last week in the journal Neurology.

The researchers looked at the genes of 278 people with Parkinson's disease and 179 people without the disease. They found that while only five per cent of the people without the disease had a mutation in the glucocerebrosidase (GBA) gene, this increased to 14 per cent amongst those with the disease. In those who developed Parkinson's disease before the age of 50, this further increased to 22 per cent. Only 10 per cent of those diagnosed after the age of 50 carried the GBA gene mutation.

Mutations in the GBA gene also cause Gaucher's disease, which is a rare disorder that causes a build-up of a fatty substance called glucocerebroside, eventually preventing organs such as the spleen and brain from working properly. Lead researcher and study author Dr Lorraine N Clark, from Columbia University in New York, said that the results 'confirm that GBA mutations are risk factors for Parkinson's disease and may lead to getting the disease at a younger age', adding: 'We found those people with GBA mutations developed Parkinson's disease nearly two years earlier than people without the gene abnormality'. Even though Parkinson's and Gaucher's are quite different incurable diseases, their causes may have genetic similarities, Clark said.

The study also analysed whether having Jewish ancestry affected the likelihood of getting Parkinson's disease at an earlier age. Some earlier studies have found that people with Eastern and Central European Jewish ancestry are more likely to have GBA gene mutations. The results showed that the gene mutation was present in 17 per cent of the study participants with Jewish ancestry, compared to only eight per cent of those without.