Parkinson disease 14 is a recessive subtype of Parkinson disease (FBhh0000004). It is one of several diseases associated with the human gene PLA2G6. See the human disease model report for neurodegenerative disease, PLA2G6-related (FBhh0000243).
[updated Apr. 2016 by FlyBase; FBrf0222196]
Parkinson disease (PD) is a neurodegenerative disease usually typified by slow onset in mid to late adulthood; there are also early-onset and juvenile forms of the disease. Symptoms worsen over time and include resting tremor, muscular rigidity, bradykinesia [abnormal slowness of movement], and postural instability [impaired balance and coordination]; additional symptoms may include postural abnormalities, dysautonomia [symptoms caused by malfunction of the autonomic nervous system], dystonic cramps, and dementia. Parkinson disease is the second-most common neurodegenerative disease (after Alzheimer disease), affecting approximately 1% of the population over 50 (Polymeropoulos et al., 1996, pubmed:8895469). [from MIM:168600; 2013.07.23]
Parkinson disease is described as early-onset disease if signs and symptoms begin before age 50. Early-onset cases that begin before age 20 may be referred to as juvenile-onset disease. [from Genetics Home Reference, GHR_condition:parkinson-disease, 2015.02.13]
[PARKINSON DISEASE 14, AUTOSOMAL RECESSIVE; PARK14](https://omim.org/entry/612953)
[PHOSPHOLIPASE A2, GROUP VI; PLA2G6](https://omim.org/entry/603604)
See general description above. See, also, the description of neurodegeneration with brain iron accumulation (FBhh0000223).
PARK14 is caused by homozygous mutation in the PLA2G6 gene (phospholipase A2, group VI). Mutations in the PLA2G6 gene also cause forms of neurodegeneration with brain iron accumulation. [from MIM:612953; 2016.04.05]
Patients diagnosed with PARK14 show little or no brain iron accumulation.
The endocytic membrane-trafficking pathway and disruption of synaptic vesicle endocytosis appear to play major roles in the risk of Parkinson disease. A substantial amount of genetic variation in PD and parkinsonism has been associated with vesicle trafficking via endosomal gene alterations. (Bandres-Ciga et al., 2019, pubmed:30675927; Nguyen et al., 2019, pubmed:30509690). Relevant genes include DNAJC6 (see FBhh0000594, FBhh0000593), SYNJ1 (see FBhh0000626), GAK (see FBhh0000593) and SH3GL2, which are linked to clathrin-coated vesicles, and VPS35 (see FBhh0000030) and DNAJC13 (see FBhh0001155), which participate in recycling components from the endosomes to the Golgi. In addition, LRRK2 (see FBhh0000011) and PLA2G6 (see FBhh0000243, FBhh0000232) have been shown to interact with genes involved in endocytic membrane trafficking.