1. Analysis of Methylenetetrahydrofolatereductase (MTHFR) Polymorphisms
(C677T & A1298C) in
Recurrent Pregnancy Loss (RPL)
Authors - Balasubramaniam Anujan,
Ranmalee Amarasekara &
Subeshala Kotalawala
Affiliation – BMS School of Science,
Colombo 06
Country – Sri Lanka

2. Recurrent Pregnancy Loss (RPL)
Analysis of Methylenetetrahydrofolatereductase (MTHFR) Polymorphisms (C677T & A1298C) in
Recurrent Pregnancy Loss (RPL)
Analysis
Background
Recurrent Pregnancy loss (RPL) is a multifactorial disorder responsible for 15% of pregnancy failures.
WHO defined miscarriage as loss of the fetus or embryo weighting less than 500 g which would normally be at complete weeks of gestation” (Vanilla et al., 2015).
The underlying etiology of RPL remains unknown and pathogenesis of RPL is complicated.
Research studies suggest genetic factors to be highly associated with recurrent miscarriages (Cao et al., 2014).
Literature suggests that MTHFR polymorphisms to be associated with RPL, C677T and A1298C polymorphisms are the two common mutations involved in RPL.
However the specific polymorphisms of MTHFR gene associated with RPL is still debatable.
Table 1. Data Analysis Sheet
Year
Author
Journal
Place of study
Sample Size
Type of Sample
Source
Methods & Detection
Mutation Found
Mutation Type and
Analysis
2013
Cao et al.,
Gene 514 (2013)
China
46 reports 3559 URPL cases, 5097 healthy controls
Maternal
Blood
Meta-analysis
MTHFR C677T
1298CC mutation was 9% in both samples
East Asians people are higher risk of URPL with 677TT genotype
2015
Hubacek, J.A et al.,
Clin Chim Acta 440 p
Slavonia
464 samples 486 controls
aborted samples
PCR-RFLP
MTHFR C677T MTHFR A1298C
Carriers with dominant allele of these polymorphisms were associated with higher risk of abortion
Distinct combination of MTHFR could be associated with higher risk of abortions in Caucasians
Continues…..
Figure1. Molecular location of MTHFR Gene
Platelet aggregation
Endothelial damage
Vasculopathy in placental vasculature
Influencing utero-placental circulation selectively
Spontaneous Abortion
Expand tHcy
Decrease enzyme activity
MTHFR polymorphisms
C677T A1298C
Results
Objective
Aim of the study was to determine the frequencies of MTHFR C677T and A1298C MTHFR polymorphisms associated with RPL
Methodology
Identification and Eligibility of Relevant Studies
Articles (n=35) published between the years 2005 to 2015, were selected for this review. Case control studies (30), meta-analysis (4) and a nested case control study were taken into account.
Study Design
Figure 2. Ratio of the case studies
A positive MTHFR polymorphisms associated with RPL were seen in 75% (26/35) of the study (p = 0.002)
Eligible Studies (n=35)
C677T MTHFR polymorphism
in RPL
50%
A1298C MTHFR polymorphism in RPL
15%
Data Extraction
Year
Author
Journal
Place of study
Sample Size
Type of Sample
Source
Methods & Detection
Mutation Found
Mutation Type and
Analysis
2013
Cao et al.,
Gene 514 (2013)
China
46 reports 3559 URPL cases, 5097 healthy controls
Maternal
Blood
Meta-analysis
MTHFR C677T
1298CC mutation was 9% in both samples
East Asians people are higher risk of URPL with 677TT genotype
2015
Hubacek, J.A et al.,
Clin Chim Acta 440 p
Slavonia
464 samples 486 controls
aborted samples
Tissue
PCR-RFLP
MTHFR C677T MTHFR A1298C
Carriers with dominant allele of these polymorphisms were associated with higher risk of abortion
Distinct combination of MTHFR could be associated with higher risk of abortions in Caucasians
Continues…..
35%
Data such as year, authors,
journal name, place of study, sample size,
source, methodology used,
mutations found,
Mutation type were extracted
Figure 3. Percentage of frequency of both
polymorphisms in RPL
Among the positive studies, 35% (9/26) had both C677T and A1298C polymorphisms.
C677T polymorphism was the only polymorphism associated with RPL in 50% (13/26) of cases, while 15% (4/26) found A1298C polymorphism associated with RPL.
Study subjects
17,780 cases and 22,346 controls were considered as study subjects
Analysis

3. Significant Findings Conclusion References
MTHFR polymorphisms were found to be the first common mutation to be involved in RPL ( Ozdemir et al., 2012)
MTHFR polymorphisms were significantly associated with RPL ( p= 0.002).
MTHFR C677T polymorphism was the most prevalent polymorphism compared to A1298C polymorphism ( p= 0.043).
C677T polymorphism has been denoted as a risk factor for RPL because of expand tHcy
Accordingly, the C677T polymorphism could be used as a genetic marker for early diagnosis of RPL.
Study further suggests, paternal screening is equally important as maternal screening in the early diagnosis of RPL.
C677 homozygous genotype was significantly higher in the RPL women in China and East Asia (p=0.003)
References
Cao, Y., Zhang, Z., Zheng, Z., Yuan, W., Wang, J., Liang, H., Chen, J., Du, J. & Shen, Y. (2014) The association of idiopathic recurrent early pregnancy loss with polymorphisms in folic acid metabolism-related genes, Genes Nutrition, 9,
Prevalence of MTHFR-C677T polymorphism present in the partners of women suffered from RPL
Recurrent Pregnancy
Loss (RPL)
Ozdemir, O., Yenicesu, G.I., Silan, F., KoKsal, B., Atik, S., Ozen, F., Gol, M. & Cetin, A. (2012) Recurrent Pregnancy Loss and Its Relation to Combined Parental Thrombophilic Gene Mutations, Genetic Testing and Molecular Biomarkers, 16,
Supplementation of enriched folate diet,
5-MTHF (200 µg per day),
folic acid (200 µg per day)
will significantly decrease the pregnancy complications
Vanilla, S., Kutty, M. & Vegi, P.K. (2015) Evidence of Paternal N5, N10 - (MTHFR) C677T Gene Polymorphism in Couples with Recurrent Spontaneous Abortions (RSAs) in Kolar District- A, Journal of Clinical and Diagnostic Research, 9, BC15-BC18.