LRRK2 gene mutation affects Parkinson's disease risk

A change in just one gene may affect the risk of Parkinson's disease. That could lead to genetic testing for Parkinson's, say scientists.

The gene in question is the LRRK2 gene. It's the topic of three studies in the Jan. 18 online edition of The Lancet.

A single mutation in the LRRK2 gene occurs in about 5% of inherited Parkinson's cases and 2% of isolated cases, experts report in The Lancet. The mutation was seen in familial Parkinson's disease as well as in patients without a family history of the disease.

The studies are from Italy, England, the U.S., Portugal, and Brazil. Two studies tracked the LRRK2 gene in patients with familial Parkinson's disease. For comparison, one of those projects also looked at the DNA of healthy people. The third study focused on people with Parkinson's disease without a family history of the disease.

All three studies suggest that the LRRK2 gene mutation affects Parkinson's disease risk.

"Our results suggest that a single LRRK2 mutation causes Parkinson's disease in 5% of individuals with family disease," say William Nichols, PhD, of Cincinnati Children's Hospital, and colleagues.

Likewise, another study linked the mutation to Parkinson's disease in four out of 61 families with the disease from Italy, Portugal, and Brazil. That's a little less than 7% of the families studied. The third study spotted the mutation in nearly 2% of isolated Parkinson's cases.

Tags: LRRK2