A quick answer to the question posed in the title of this post – is Parkinson’s hereditary? – is: sometimes.
Basically, some instances of Parkinson’s seem to be hereditary, while others (the majority) don’t. In my case, there are no past incidences of Parkinson’s in my family that we know of, and so my Parkinson’s has been labelled “idiopathic”, which means that they don’t know what caused it.
But in other cases – such as the “large Swiss family with a history of Parkinson’s disease” who were the focus of recent research reported in this Psych Central article – a genetic marker has been identified.
As Zbigniew Wszolek, M.D., one of the researchers responsible for the study of the Swiss family, says:
“Every new gene we discover for Parkinson’s disease opens up new ways to understand this complex disease, as well as potential ways of clinically managing it.”
As I understand it, the genetic causes of Parkinson’s are specific mutations in certain genes. This comes across quite well in another news article describing the same discovery, “… one of the three genes which cause late-onset Parkinson’s, at an age of about 60 years”, according to Alexander Zimprich from the Department of Clinical Neurology at the Medical University of Vienna. (A total of six genes currently identified is cited in the article; three, including this one, are “dominant”.)
The study looked at seven members of one family who have Parkinson’s:
The team discovered more than 20,000 variants of the gene in each patient. [… ] The researchers uncovered only one mutation in the VPS35 gene that could have triggered Parkinson’s in all of the seven family members.
The six implicated genes are:
- LRRK2, SNCA, VPS35
(Dominant; one copy of an altered gene in each cell is sufficient to cause the disorder.)
- PARK2, PARK7, PINK1
(Recessive; two copies of the altered genes must be present before the disorder occurs. Most often, the parents of an individual with autosomal recessive Parkinson’s each carry one copy of the altered gene but do not show signs and symptoms of the disorder.)
The research identifying VPS35 mutations in Parkinson’s, mentioned in this blog post, was conducted by researchers at a number of international centres. A selection of references to the study are noted below: