Higher incidence of C677T polymorphism of the MTHFR gene in North Indian patients with vascular disease

Highlights on Genetic Polymorphism Associated with Thromboembolic Risk; Implications in Ophthalmic and Autoimmune Disorders—A Review

The present paper explores genetic polymorphism and its association with thromboembolic retinal venous disorders, such as central/hemi-retinal vein occlusion, as well as possible correlations with other ocular findings, such as closed angle glaucoma, but also with autoimmune general disorders. In this review, we are highlighting the importance of establishing a correspondence between all of the above, since they all have complex etiopathogeneses; sometimes, when all coexist together, they could generate effects that may be very difficult to manage. There are studies supporting that genetic polymorphism, such as the variant MTHFR A1298C, may increase the risk for developing glaucoma, especially in the heterozygote model. Being aware of all these aspects may prove to be useful in patients with several associated diseases, as a combined effort between several medical specialties may prove to the benefit of these patients. Our review, completed with an exemplifying clinical case, shows that it is necessary to raise awareness of all aspects of a complex medical situation, including the genetic one, of a patient being at risk for thromboembolic episodes, for preventing them or managing them promptly and properly in the future.

Avascular Necrosis of the Humeral Head in a Patient with Methylenetetrahydrofolate Reductase 1 Gene Polymorphism: A Case Report

CASE

Atraumatic avascular necrosis (AVN) of the humeral head is a debilitating condition with an insidious onset and progressively worsening pain. We report a case of a woman who presented with left shoulder pain with a medical history of a rare genetic polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene. Advanced imaging demonstrated focal AVN of her humeral head. Treatment varies based on the stage of the disease, which, in this case, included an ultrasound-guided intra-articular corticosteroid injection and oral methylated supplementation.

CONCLUSION

In patients with no other known risk factors presenting with AVN of the humeral head, MTHFR polymorphism should be strongly considered a possible cause of AVN.

Association of MTHFR gene polymorphisms with migraine in North Indian population

Polymorphisms in MTHFR gene are mostly associated with increased levels of homocysteine in the absence of dietary folate and are a risk factor for complex neurovascular diseases like migraine. The aim of present case-control study was to determine the association between MTHFR gene polymorphisms (C667T; rs 1801133, A1298C; rs 1801131) with migraine susceptibility. In total, 100 patients with migraine (23with MA and 77 with MO) and age-sex matched 100 healthy controls were included in this study from OPD of ESIC Medical College & Hospital, Faridabad. Genotyping was done by PCR-RFLP method. Genotypic and allelic frequencies were compared by SPSS 24 version. Genotypic results indicated a non-significant increase in frequencies of CT and TT in C667T SNP in migraine patients with control (52 and 10% vs. 42 and 7%: p > 0.05), but CC genotype in A1298C was found to be a risk factor in migraine patients than controls (30 vs. 17% respectively: p < 0.05). On comparing migraine subclasses, migraine with aura (MA) and without aura (MO) with control groups, the present study suggests that in MTHFR polymorphisms, the prevalence of 677CT genotype and T allele in C667T SNP influences susceptibility to MA (p < 0.05) but not to MO. Meanwhile, CC genotype in A1298C SNP could be a risk factor for migraine patients without aura (p < 0.05).

Association of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with primary glaucoma in Saudi population

Background

Methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate metabolism is involved in DNA synthesis, DNA repair and DNA methylation. The functional polymorphism of MTHFR gene, C677T has been shown to impact various diseases and implicated as a risk factor for the development of various neurodegenerative disorders including glaucoma.

Methods

We investigated MTHFR C677T genotypes and alleles frequencies in primary glaucoma [primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG)] patients and matched healthy controls in a case-control study. Two hundred ten primary glaucoma cases were studied for MTHFR C677T polymorphism and compared with 280 controls taken from the healthy population, employing the polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). The MTHFR gene was amplified using specific primers. The PCR products (294 bp) was subsequently digested with HinfI (New England Biolabs) at 37 °C for 12 h, separated by electrophoresis on 2 % agarose gels, and visualized with ethidium bromide staining. The restriction digestion yielded 168 and 126 bp fragments for TT, 294, 168 and 126 bp fragments for CT and undigested PCR product 294 bp indicating CC genotype.

Results

We found the frequency of the genotypes and alleles of MTHFR C677T differ significantly between cases and controls. The frequencies of allele T and genotype CT were significantly higher while the frequencies of allele C and genotype CC were lower in primary glaucoma patients as compared to controls (p <0.05). Upon stratification of our results into POAG and PACG, significantly higher frequencies of allele T (19.44 %) and genotype CT (38.89 %) were found in POAG patients compared to controls (12.5 % and 25 % respectively). The frequencies of alleles and genotypes were almost similar in PACG and controls (p = 0.8).

Conclusion

This study indicates that the allele T and genotype CT of MTHFR C677T polymorphism are significantly associated with POAG while allele C and CC genotype may be protective for it. We conclude that the MTHFR C677T polymorphism increases the risk for POAG development in Saudi population and can be a genetic marker however, further studies are needed with multiple-ethnic populations affected with POAG to strengthen these findings.