In contrast to the previous report, which assumed that the 68-bp insertion introduced a premature-termination codon and resulted in a nonfunctional CBS enzyme, we found that the presence of this mutation is not associated with hyperhomocysteinemia.
To test this possibility, we studied cDNA derived from four well characterized patients with POAD, exhibiting hyperhomocysteinemia and reduced CBS activities, from four normal controls, and from four obligatory heterozygotes for CBS deficiency.
Polymorphisms of MTHFR were observed in 75% and 56% and the PAI1 -675 5G/4G polymorphism in 100% and 83% of patients with and without HHCE, respectively.
Some polymorphisms observed on the MTHFR gene cause inactivation of the MTHFR enzyme, leading to hyperhomocysteinemia and homocysteinuria, which are prominent risk factors of cardiovascular and cerebrovascular diseases.
This is the first report from Pakistan where novel as well as recurrent CBS mutations causing hyperhomocysteinemia and lens dislocation in three patients from different families are being reported with the predicted effect of the risk allele of the MTHFR SNP in causing hyperhomocysteinemia.
In SLE patients, both hyperhomocysteinemia and MTHFR 677TT genotype were identified as independent contributors for plaque formation, following adjustment for traditional cardiovascular risk factors and disease related features, including age, sex, BMI, cholesterol and triglyceride levels, presence of arterial hypertension, smoking (pack/years), disease duration and total steroid dose [OR 95% (CI): 5.8 (1.0-35.8) and 5.2 (1.1-24.0), respectively].
While HHcys and decreased %DMA were associated with increased risk for skin lesions, and MTHFR 677 C ➔ T was a strong predictor of HHcys, MTHFR 677 C ➔ T was not associated with skin lesion risk.
The MTHFRrs1801133 CT genotype, TT genotype and T allele; the MTHFRrs1801131 AC genotype, CC genotype and C allele; the MTRR rs1801394 GA genotype, GG genotype and G allele; and the MTRR rs162036 AG genotype and AG+GG genotypes were associated with the efficacy of folic acid therapy for HHcy (P<0·05).
Methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in the hyperhomocysteinemia, which is a risk factor related to the occurrence of congenital heart defect (CHD).
Mutations in methylenetetrahydrofolate reductase (MTHFR) gene lead to decreased activity of the enzyme and hyperhomocysteinemia, which then induces platelet aggregation by promoting endothelial oxidative damage, possibly resulting in adverse effect on maintenance of pregnancy.
A strong association between Hhcy and MTHFR TT genotype was observed (OR = 7.7, 95%CI:2.8-20.9) where all β-TM patients with TT genotype were hyperhomocystienemic (≥ 15 μmol/l) and having sub-optimal folate level than those with CT or CC genotypes.
The interaction analysis showed that age and peripheral arterial disease played an interactive role in the association between HHcy and AAA, while drinking status played an interactive role in the association between MTHFRC677T polymorphism and AAA.
The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most investigated of the genes associated with chronic human diseases because of its associations with hyperhomocysteinemia and toxicity.
Both of the risky MTHFR haplotypes were correlated with decreased MTHFR gene expression and elevated homocysteine concentrations, indicating a genetic component for hyperhomocysteinemia.
To investigate the distribution of MTHFRC677T and A1298C as well as PON1 Q192R gene polymorphisms, known to be involved in hyperhomocysteinemia-related cardiovascular risk, in elite athletes.
Severe 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency is caused by mutations in the MTHFR gene and results in hyperhomocysteinemia and varying severity of disease, ranging from neonatal lethal to adult onset.
It is probable that the combination of pronounced dietary folate deficiency, an MTHFR 'null allele' and the 677 T variant is sufficient to explain both the moderate hyperhomocysteinaemia and the clinical presentation in this patient.