Parkinson's Disease Genetic Health Risk Testing

Most cases of Parkinson's disease occur in people without a family history of the disease. These sporadic cases may not be inherited or have an unknown inheritance pattern.

In familial cases of Parkinson's disease, the inheritance pattern varies according to the altered gene. If the LRRK2 or SNCA genes are involved, the disorder is inherited in a dominant somatic pattern, meaning that one altered gene per cell is enough to cause the disease. In most cases, 

a parent of affected individuals is in this condition.

If the PARK7, PINK1, or PRKN genes are involved, Parkinson's disease is inherited in a recessive somatic pattern. This type of inheritance means that two genes are changed in each cell. In most cases, the parents of individuals with somatic recessive Parkinson's disease carry an altered gene without any signs and symptoms.

When genetic changes reduce the risk of developing Parkinson's, the inheritance pattern is often unknown.