Parkinson's disease (PD) is one of the most common neurodegenerative diseases. 
Majority of PD are sporadic, for which genetic causes remain largely unknown. 
Alpha-synuclein, the main component of Lewy bodies, plays a central role in the 
PD pathogenesis. Macroautophagy is a highly conserved cellular process that 
digests dysfunctional macromolecules and damaged organelles. Accumulating 
evidence indicates that macroautophagy (hereafter referred to as autophagy) is 
involved in alpha-synuclein degradation. Dysregulation of autophagy has been 
observed in the brain tissues from PD patients and animal models. We 
hypothesized that change expression levels of autophagy-related genes (ATG), 
including ATG5, may contribute to PD. In this study, we genetically and 
functionally analyzed the ATG5 gene promoter in groups of sporadic PD patients 
and ethnic-matched healthy controls. A novel heterozygous variant, 106774459T>A, 
was identified in one female patient, but in none of controls, which 
significantly enhanced transcriptional activities of the ATG5 gene promoter. 
Furthermore, ATG5 gene expression level in the PD patient was significantly 
elevated than that in controls. Four novel heterozygous variants, 106774423C>A, 
106774418C>A, 106774382C>A and 106774206G>A, were only found in controls. The 
variant, 106774464C>T, and SNP-106774030A>G (rs510432) were found in PD patients 
and controls with similar frequencies. Collectively, the variant identified in 
PD patient may change ATG5 protein levels and alter autophagy activities, 
contributing to PD onset as a risk factor.