Significant association was found between MTHFR A1298C polymorphism and PD </span>risk in the overall population in the dominant (OR=1.168, 95%CI: 1.008-1.353, P=0.039) and heterozygous model (OR=1.172, 95%CI: 1.004-1.367, P=0.044).
The MTHFR A1298C polymorphism had no effect on PD age at onset (p = 1.0) while there was a significant association with MTHFR C677T (p = 0.019 Bonferroni-adjusted post hoc) showing an earlier onset in CC as compared with TT.(p = 0.024).
Genetic C677T and A1298C polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR) and levodopa therapy in Parkinson's disease (PD) may increase homocysteine (Hcy) level.
In AD there were significant differences of the levels of only Cys (GG, MTHFR, G1793A) and Met/Hcy (AA, MTHFD1, G1958A) whereas in PD there were more significant differences of the levels of thiols: Hcy [MTHFR: CT (C677T) and GG (G1793A); MTR, AG (A2756G)], Met [MTR, AA (A2756G)], Cys [MTR, AG (A2756G)], and Met/Hcy [MTHFR: CC, CT (C677T) and AA (A1298C), and GG (G1793A); MTHFD1 AA(G1958A); MTR AA(A2756G)].