Association between polymorphism in the MTHFR gene and encephaloduroarteriosynangiosis-induced collateral circulation formation

OBJECTIVE This study aimed to investigate whether high homocysteine (Hcy) levels associated with the MTHFR gene influence the formation of the collateral vascular network in patients with moyamoya disease (MMD) after encephaloduroarteriosynangiosis (EDAS) by influencing the number of endothelial progenitor cells (EPCs) in peripheral blood. METHODS A total of 118 Chinese patients with bilateral primary MMD were prospectively included. Blood samples were collected from the anterior cubital vein before surgery, and MTHFR rs9651118 was genotyped using high-throughput mass spectrometry to determine the genotype of the test specimen. Serum Hcy and EPC levels were measured, the latter with flow cytometry. Digital subtraction angiography was performed 6 months after EDAS, and the formation of collateral circulation was evaluated using the Matsushima grade system. The correlations between MTHFR rs9651118 genotype, Hcy and EPC levels, and Matsushima grade were compared. RESULTS Among the 118 patients, 53 had the TT genotype (wild type) of MTHFR rs9651118 , 33 TC genotype (heterozygous mutation), and 32 CC genotype (homozygous mutation). The mean ± SD Hcy level was 13.4 ± 9.5 μmol/L in TT patients, 9.8 ± 3.2 μmol/L in TC patients, and 8.9 ± 2.9 μmol/L in CC patients (p < 0.001). The level of EPCs in the venous blood of TT patients was 0.039% ± 0.016%, that of TC patients 0.088% ± 0.061%, and that of CC patients 0.103% ± 0.062% (p < 0.001). When the rs9651118 gene locus was mutated, Matsushima grade was better (p < 0.001) but there was no difference between heterozygous and homozygous mutations. CONCLUSIONS The results suggest that the MTHFR rs9651118 polymorphism is a good biomarker for collateral vascular network formation after EDAS in MMD patients.