Table 1.

Phenotypes of different monogenic Parkinson’s disease with motor and non-motor symptoms.

Gene	Disease onset	Inheritance	Motor symptoms	Non-motor symptoms
PARK1/PARK4-SNCA	Early	Autosomal dominant	Rapid progression, good levodopa response; most often experience bradykinesia and rigidity; only about 30% report resting tremor and postural instability.	Cognitive decline is the most common, followed by depression, autonomic symptoms, and psychotic symptoms; includes olfactory disorders.
PARK8-LRRK2	Late	Autosomal dominant/autosomal recessive	Good response to levodopa; postural instability; gait difficulty phenotype; progressed at a rate similar to iPD.	Fewer nonmotor manifestations than iPD.
PARK17-VPS35	Early	Autosomal dominant	Phenotype similar to iPD; Case reports only Tremor-predominant PD.	Non-motor symptoms similar to iPD.
PARK2-Parkin	Juvenile or early	Autosomal recessive	Slow progress; good response to dopaminergic treatment, usually complicated by dystonia and prominent freezing of gait; with sleep benefit on most symptoms.	Less severe than in iPD; less olfactory dysfunction; performed better on the Mini-Mental State Examination, clinical dementia rating, attention, memory, and visuospatial performance; but may have more serious impulse control disorders.
PARK6-PINK1	Juvenile or early	Autosomal recessive	Progresses slowly; levodopa responds well and persistent; sleep benefit; the common symptom is bradykinesia and rigidity; fewer pyramidal signs or hyperreflexia.	Psychiatric symptoms are more prominent; include anxiety and depression, but cognitive impairment is less involved; Hyposmia seems to be common.
PARK7-DJ-1	Juvenile or early	Autosomal recessive	Good levodopa response; dystonia is particularly common; others include postural tremor.	The non-motor symptoms are more prominent, including depression, anxiety, and other mental illness, cognitive decline.
GBA	Early	Autosomal dominant	Similar to iPD, but the onset is earlier and the course is more serious.	Non-motor symptoms are more prominent than iPD; cause more serious cognitive impairments, working memory, executive function, and visual-spatial ability. The incidence of anxiety and depression is high, autonomic dysfunction may be more severe, and olfactory disturbance is similar to iPD; are associated with idiopathic RBD and possible RBD in PD patients.