Association of thrombophilic genes (MTHFR, MTR and MTRR) polymorphisms and homocysteine level in relation to the increased risk of thrombosis among COVID-19 patients

Abstract

Background

Patients with COVID-19 have an increased risk of thrombosis and coagulopathy. Homocysteine, an amino acid essential to coagulation, is thought to be involved in such conditions, as its level is mediated by the presence of some single nucleotide polymorphisms (SNPs) in certain genes including MTHFR, MTR and MTRR.

Aim

The current study aimed to assess the significant role of MTHFR (C677T and A1298C), MTR A2756G and MTRR A66G SNPs as risk factors for thrombosis among Egyptian COVID-19 patients and their effect on homocysteine level.

Subjects and methods

This case-control study was carried out on 90 Egyptian COVID-19 cases, divided into 45 non-complicated cases and 45 complicated cases with thrombosis, in addition to 80 healthy control individuals. DNA was isolated from blood samples of all the participants. The genotyping was performed using real-time PCR; in addition, serum homocysteine level was estimated.

Results

The MTHFR (C677T and A1298C), MTR A2756G and MTRR A66G variants revealed a significant higher risk of thrombosis under different genetic models including the homozygous comparison of the co-dominant (20 % vs. 2.3 %, OR = 15.88, p = 0.007), the dominant (62.2 % vs. 33.3 % OR = 3.29, p = 0.006) and the allelic models (41.1 % vs. 17.8 %, OR = 3.2, p < 0.001) for MTHFR C677T and also the dominant (77.8 % vs. 51.1 %, OR = 3.3, p = 0.008) and the allelic models (52.2 % vs. 31.1 %, OR = 2.4, p = 0.004) for MTHFR A1298C. In addition, the heterozygous comparison of the co-dominant (60 vs. 11.1, OR = 12.7, p < 0.001), the dominant (62.2 % vs. 11.1 %, OR = 13.1, p < 0.001) and the allelic models (32.2 % vs. 5.6 %, OR = 8.08, p < 0.001) for MTR A2756G and the heterozygous and homozygous comparisons of the co-dominant model [(53.3 % vs. 31.1 %, OR = 3.4, p = 0.03) and (13.4 % vs. 2.2 %, OR = 12.0, p = 0.049), respectively], the dominant (66.4 % vs. 33.3 %, OR = 4.0, p = 0.001) and the allelic models (40 % vs. 17.8 %, OR = 3, p = 0.001) for MTRR A66G. Moreover, MTHFR (C677T and A1298C), MTR A2756G, and MTRR A66G variants were also associated with high levels of serum homocysteine (p = 0.045, 0.001, 0.005 and 0.039, respectively). The homocysteine level was related to the disease severity by its correlation with higher LDH (rs = 0.49, p < 0.001), CRP (rs = 0.44, p < 0.001), IL-6 (rs = 0.46, p < 0.001) and D-dimer (rs = 0.66, p < 0.001) levels. The multivariate regression analysis showed that homocysteine and the dominant models of MTHFR (C677T and A1298C), MTR A2756G and MTRR A66G were independent predictors of susceptibility to thrombosis among COVID-19 patients [(OR = 1.02, p = 0.007), (OR = 1.15, p = 0.043), (OR = 1.2, p = 0.024), (OR = 1.42, p < 0.001), (OR = 1.19, p = 0.021), respectively].

Conclusion

MTHFR (C677T and A1298C), MTR A2756G, and MTRR A66G gene variants were associated with high homocysteine and D-dimer levels that carried a risk for thrombosis among COVID-19 patients and associated with the disease progression.