PARKIN Mutation Carriers Progress Slower than Idiopathic PARKINSON’S DISEASE
If there is any such thing as good news in PARKINSON’S DISEASE, perhaps it is that people who have young-onset and carry the autosomal recessive gene for PARKIN mutations have a slower decline of motor symptoms and maintain higher cognitive functioning. While being diagnosed with young onset PARKINSON’S DISEASE is certainly not good news, these people may benefit from the assurance that their disease will progress more slowly and that they are at a lower risk for developing dementia than people diagnosed with idiopathic PARKINSON’S DISEASE.
A study of 44 subjects over a period of 14 years compared 21 subjects who carried the PARKIN mutation to 23 subjects who did not. Those who carried the mutation had an earlier age of onset and were younger than the subjects in the idiopathic cohort. These young onsets performed better on Mini-Mental State Examinations and had lower scores (indicating better performance) in Clinical Dementia Rating tests. They also scored higher in cognitive domains and did better in tests of visuospatial relationships, attention and memory. Motor performances were also better than those in the idiopathic cohort.
Primary researcher Dr. Roy N. Alcalay who is with Columbia University in New York says “our findings have important implications for genetic testing and for the counseling of homozygotes and compound heterozygotes that carry PARKIN mutations.” He also stresses that this was a small, cross sectional study and that more longitudinal studies need to be done to confirm these findings.
Alcalay, R.N, et al; Cognitive and Motor Function in Long-Duration PARKIN-Associated Parkinson Disease; JAMA Neurol 2014; 71(1) 62-67, doi:10.1001/jamaneurol.1023.4498
Review by Marcia McCall