Genes which may influence the onset age of Parkinson’s disease have been identified. The research is the first to identify genes contributing to the variation in onset age.
Parkinson’s disease incidence increases with age from 1.7 /10,000 person-years between ages 50 to 59 to 9.3/10,000 person-years between ages 70 to 79 and has a prevalence of approximately 1.8 percent among people over the age of 65. While the average age of onset of Parkinson’s disease is approximately 60 years, there is wide variation, with some individuals experiencing onset before age 20 and others not until after age 90. Onset of Parkinson’s disease has been shown to be correlated between siblings with Parkinson’s disease, suggesting that genetic modifiers influence onset age.
The researchers performed analyses using genotypes generated with the Illumina HumanCNV370Duo array in a sample of 857 unrelated, familial Parkinson’s disease cases. Subsequently, a meta-analysis of imputed Single Nucleotide polymorphisms (SNPs) was performed combining the familial Parkinson’s disease data with that from a previous genome-wide associated study (GWAS) of 440 idiopathic Parkinson’s disease cases. They identified the 15q26.2 region as well as the gene AAK1 related to the previously observed Parkinson’s disease susceptibility gene, GAK as areas that would benefit from further examination.
According to the researchers, identifying these areas as associated with both Parkinson’s disease onset age and susceptibility may provide insight into the disease mechanisms and processes for delaying disease onset.
References:
1. Jeanne C Latourelle, et al. Genomewide association study for onset age in Parkinson disease. BMC Medical Genetics 2009, 10:98doi:10.1186/1471-2350-10-98.
