Is Parkinson disease inherited ?
Most cases of Parkinson disease occur in people with no apparent family history of the disorder. These sporadic cases may not be inherited, or they may have an inheritance pattern that is unknown.  Among familial cases of Parkinson disease, the inheritance pattern differs depending on the gene that is altered. If the LRRK2 or SNCA gene is involved, the disorder is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.  If the PARK2, PARK7, or PINK1 gene is involved, Parkinson disease is inherited in an autosomal recessive pattern. This type of inheritance means that two copies of the gene in each cell are altered. Most often, the parents of an individual with autosomal recessive Parkinson disease each carry one copy of the altered gene but do not show signs and symptoms of the disorder.  When genetic alterations modify the risk of developing Parkinson disease, the inheritance pattern is usually unknown.