Parkinson’s disease and related disorders [26 genes]

Parkinsonism refers to a group of neurological syndromes characterized by:

• Bradykinesia
• Muscle stiffness
• Resting tremor
• Postural instability

Parkinson’s disease is the most common form of parkinsonism and the second most frequent neurodegenerative disease after Alzheimer’s disease. It is clinically characterized by these four cardinal motor symptoms, as well as by a good response to treatment with levodopa.

Other types of atypical parkinsonism and Parkinson-plus conditions (such as progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy, or Lewy body dementia) are covered in the general panel.

Its prevalence is estimated to be between 1%-2% of the population at age 65 and about 4% at age 85. Approximately 15% of cases are familial, although some studies suggest that up to 60% of sporadic cases could be explained by genetic risk factors (Hamza et al., 2010). It is currently considered a multifactorial disease, with numerous environmental and genetic factors involved.

The most commonly involved monogenic determinants have been selected for a basic panel for this disease, including SNCA, LRRK2, and VPS35 (with autosomal dominant transmission and generally late onset), and PRKN (PARK2), PINK1, PARK7 (DJ1), and VPS13C (with autosomal recessive transmission and an earlier onset). This panel also includes the GBA gene, which is associated with a greater risk of developing the disease.

Patients with clinical suspicion of Parkinson’s disease / parkinsonism.