A research team based in France has identified new gene variants that may predict Parkinson’s disease life expectancy. The groundbreaking discovery may help to forecast outcomes for patients with the neurodegenerative condition.
The team, led by Dr Aymeric Lanore from the Paris Brain Institute at the Sorbonne Université, included scientists from four institutes in Paris and analysed the health records of more than 2000 Parkinson’s disease patients. The study illuminated that Parkinson’s disease life expectancy may be predicted by genetic variants, providing unprecedented insights into the disease’s progression.
The debilitating effects of Parkinson’s disease
Parkinson’s disease is a brain condition caused by a loss of nerve cells that results in a reduction of an essential chemical called dopamine. This gradual loss of dopamine causes a range of the characteristic motor symptoms of the condition, including involuntary shaking of body parts, muscle stiffness, slowness of movement, and progressive cognitive decline.
Current estimates suggest that in Europe alone, there are around 1.2 million people living with Parkinson’s disease, which is projected to double by 2030. Some forms of Parkinson’s are triggered by a single gene variant – known as monogenic – which is responsible for 5% of cases and appears not to be hereditary.
The most predominant genetic variant associated with Parkinson’s disease is the LRRK2 gene, with people who carry it in later life having a 70% increased risk of developing Parkinson’s by the age of 80.
Predicting Parkinson’s disease life expectancy
For their investigation, the researcher utilised health records of 2,037 Parkinson’s disease patients from the point of their initial hospital visit, findings two mutations that potentially forecast Parkinson’s disease life expectancy.
The scientists calculated hazard ratios to compare the survival rates of patients with a genetic mutation with a control group who did not have a genetic mutation. The results signified that individuals with either an LRRK2 or PRKN gene had an extended survival time than patients without a gene mutation, with the hazard ratio of death being 0.5 and 0.42, respectively.
In contrast, patients who carried the SNCA or GBA mutations had a significantly shorter life expectancy from Parkinson’s disease than those without the mutation – a hazard ratio of death of 10.2 and 1.36, respectively.
Dr Lanore commented: “The results suggest the shorter survival of SNCA and GBA patients may be related to the faster motor progression of the disease and earlier development of cognitive impairment. These are important new insights which could help the development of new drugs targeting these genetic variants to slow down or stop the disease.
“These findings not only help increase our understanding of what drives the progression of Parkinson’s disease, but they may also enable clinicians to have honest conversations with their patients about expected survival times – just as cancer patients are told their prognosis. This can empower patients to make decisions about their care and the time they may have left.”