Relationship of the MTHFD1 (rs2236225), eNOS (rs1799983), CBS (rs2850144) and ACE (rs4343) gene polymorphisms in a population of Iranian pediatric patients with congenital heart defects

Novel and deleterious nucleotide variations in the HAND1 gene probably affect miRNA target sites and protein function in pediatric patients with congenital heart disease

BACKGROUND

Congenital heart disease (CHD) is the most prevalent developmental defect and principal cause of infant mortality and affects cardiac and large blood vessel structures in approximately 1% of live births worldwide. To date, numerous studies have related critical genetic dysfunctions to the pathogenesis of CHDs. However, the genetic basis underlying CHD remains largely unknown. In the present study, we investigated the association of nucleotide variations in coding and noncoding regions of the HAND1 gene with the risk of CHD. The HAND1 gene, encoding a helix-loop-helix transcription factor, is particularly relevant for mechanisms underlying CHD since it plays a significant role in heart development.

METHODS AND RESULTS

The genomic DNA of 150 unrelated pediatric patients with CHD was screened by PCR-SSCP and direct sequencing. Four novel and heterozygous missense mutations were identified in the first exon, with three causing amino acid substitutions (p.Val149Met, p.Tyr142His, and p.Leu146Met). In-silico analysis also indicated their deleterious impact on protein structure and function. In addition, we identified five novel nucleotide variants in the 3'UTR region (c.*461, c.*342, c.*529, c.*448, c.*593), potentially altering the target sites of miRNAs. These changes include the loss of certain target sites and the acquisition of new ones.

CONCLUSIONS

These findings confirm the phenotypic association between CHDs and HAND1 mutations and can pave the way for developing new preventive and therapeutic strategies.

eNOS plays essential roles in the developing heart and aorta linked to disruption of Notch signalling

eNOS (NOS3) is the enzyme that generates nitric oxide, a signalling molecule and regulator of vascular tone. Loss of eNOS function is associated with increased susceptibility to atherosclerosis, hypertension, thrombosis and stroke. Aortopathy and cardiac hypertrophy have also been found in eNOS null mice, but their aetiology is unclear. We evaluated eNOS nulls before and around birth for cardiac defects, revealing severe abnormalities in the ventricular myocardium and pharyngeal arch arteries. Moreover, in the aortic arch, there were fewer baroreceptors, which sense changes in blood pressure. Adult eNOS null survivors showed evidence of cardiac hypertrophy, aortopathy and cartilaginous metaplasia in the periductal region of the aortic arch. Notch1 and neuregulin were dysregulated in the forming pharyngeal arch arteries and ventricles, suggesting that these pathways may be relevant to the defects observed. Dysregulation of eNOS leads to embryonic and perinatal death, suggesting mutations in eNOS are candidates for causing congenital heart defects in humans. Surviving eNOS mutants have a deficiency of baroreceptors that likely contributes to high blood pressure and may have relevance to human patients who suffer from hypertension associated with aortic arch abnormalities.

Association between NOS3 gene polymorphisms and genetic susceptibility to congenital heart Disease: A systematic review and meta-analysis

BACKGROUND

Endothelial nitric oxide (NO) produced by endothelial Nitric Oxide Synthase (eNOS) can promote the expression of pro-angiogenic cytokines and is favorable for angiogenesis. However, the relationship between NOS3 gene polymorphisms and genetic susceptibility to congenital heart disease (CHD) was still unclear.

METHODS

We searched five databases including Pubmed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang, to find all studies on NOS3 gene polymorphisms and CHD. Rstudio was used to merge the data included in the study to obtain OR, 95%CI, and forest plots.

RESULTS

Five relevant literatures were included, including three sites of NOS3 gene, rs1799983 (G894T), rs2070744 (T-786C), and rs7830 (G10T). Several models including the homozygous model of rs1799983 (G894T) gene polymorphism (TT VS GG: OR = 1.602, 95%CI: 1.098 ∼ 2.337, P = 0.027), rs7830 (G10T) gene polymorphism allele model (A VS C: OR = 1.171, 95%CI: 1.029 ∼ 1.333, P = 0.017), homozygous model (AA VS CC: OR = 1.474, 95%CI: 1.122 ∼ 1.936, P = 0.005) and implicit model (AA VS CC + AC: OR = 1.451, 95%CI: 1.133 ∼ 1.859, P = 0.003) indicated that there was a correlation. The results of the combined analysis of each gene model of rs2070744 (T-786C) gene polymorphism sites were not statistically significant, and their P values were all>0.05.

CONCLUSION

rs1799983 (G894T) and rs7830 (G10T) polymorphic sites might play a role in the susceptibility of sporadic congenital heart disease and increase the risk of CHD. Yet, it is still necessary to expand the sample size and conduct more prospective/retrospective studies to confirm whether the rs2070744 (T-786C) polymorphism tended to increase the incidence of CHD.

Association of Maternal Folate Intake and Offspring MTHFD1 and MTHFD2 Genes with Congenital Heart Disease

Existing evidence supported that congenital heart defect (CHD) was associated with a combination of environmental and genetic factors. Based on this, this study aimed at assessing the association of maternal folic acid supplementation (FAS), genetic variations in offspring methylenetetrahydrofolate dehydrogenase (MTHFD)1 and MTHFD2 genes, and their interactions with CHD and its subtypes. A hospital-based case-control study, including 620 cases with CHD and 620 healthy children, was conducted. This study showed that the absence of FAS was significantly associated with an increased risk of total CHD and its subtypes, such as atrial septal defect (ASD). FAS during the first and second trimesters was associated with a significantly higher risk of CHD in offspring compared to FAS during the three months prior to conception. The polymorphisms of offspring MTHFD1 and MTHFD2 genes at rs2236222, rs11849530, and rs828858 were significantly associated with the risk of CHD. Additionally, a significantly positive interaction between maternal FAS and genetic variation at rs828858 was observed for the risk of CHD. These findings suggested that pregnant women should carefully consider the timing of FAS, and individuals with higher genetic risk may benefit from targeted folic acid supplementation as a preventive measure against CHD.

[Association of maternal MTHFD1 and MTHFD2 gene polymorphisms with congenital heart disease in offspring]

OBJECTIVES

To study the association of maternal methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) gene polymorphisms with congenital heart disease (CHD) in offspring.

METHODS

A hospital-based case-control study was conducted. The mothers of 683 children with CHD alone who attended Hunan Children's Hospital, from November 2017 to March 2020 were enrolled as the case group, and the mothers of 740 healthy children who attended the same hospital during the same period and did not have any deformity were enrolled as the control group. A questionnaire survey was performed to collect related exposure data, and then venous blood samples (5 mL) were collected from the mothers to detect MTHFD1 and MTHFD2 gene polymorphisms. A multivariate logistic regression analysis was used to evaluate the association of MTHFD1 and MTHFD2 gene polymorphisms with CHD. The four-gamete test in Haploview 4.2 software was used to construct haplotypes and evaluate the association between haplotypes and CHD. The generalized multifactor dimensionality reduction method and logistic regression analysis were used to examine gene-gene interaction and its association with CHD.

RESULTS

The multivariate logistic regression analysis showed that maternal MTHFD1 gene polymorphisms at rs11849530 (GA vs AA: OR=1.49; GG vs AA: OR=2.04) andat rs1256142 (GA vs GG: OR=2.34; AA vs GG: OR=3.25) significantly increased the risk of CHD in offspring (P<0.05), while maternal MTHFD1 gene polymorphisms at rs1950902 (AA vs GG: OR=0.57) and MTHFD2 gene polymorphisms at rs1095966 (CA vs CC: OR=0.68) significantly reduced the risk of CHD in offspring (P<0.05). The haplotypes of G-G-G (OR=1.86) and G-A-G (OR=1.35) in mothers significantly increased the risk of CHD in offspring (P<0.05). The gene-gene interaction analyses showed that the first-order interaction between MTHFD1 rs1950902 and MTHFD1 rs2236222 and the second-order interaction involving MTHFD1 rs1950902, MTHFD1 rs1256142, and MTHFD2 rs1095966 might be associated with risk of CHD (P<0.05).

CONCLUSIONS

Maternal MTHFD1 and MTHFD2 gene polymorphisms and their haplotypes, as well as the interaction between MTHFD1 rs1950902 and MTHFD1 rs2236222 and between MTHFD1 rs1950902, MTHFD1 rs1256142, and MTHFD2 rs1095966, are associated with the risk of CHD in offspring.

Association of MTHFD1 gene polymorphisms and maternal smoking with risk of congenital heart disease: a hospital-based case-control study

Background

MTHFD1 gene may affect the embryonic development by elevated homocysteine levels, DNA synthesis and DNA methylation, but limited number of genetic variants of MTHFD1 gene was focused on the association with congenital heart disease (CHD). This study examined the role of MTHFD1 gene and maternal smoking on infant CHD risk, and investigated their interaction effects in Chinese populations.

Methods

A case-control study of 464 mothers of CHD infants and 504 mothers of health controls was performed. The exposures of interest were maternal tobacco exposure, single nucleotide polymorphisms (SNPs) of maternal MTHFD1 gene. The logistic regression model was used for accessing the strength of association.

Results

Mothers exposed to secondhand smoke during 3 months before pregnancy (adjusted odds ratio [aOR] = 1.56; 95% confidence interval [CI]: 1.13–2.15) and in the first trimester of pregnancy (aOR = 2.24; 95%CI: 1.57–3.20) were observed an increased risk of CHD. Our study also found that polymorphisms of maternal MTHFD1 gene at rs1950902 (AA vs. GG: aOR = 1.73, 95% CI: 1.01–2.97), rs2236222 (GG vs. AA: aOR = 2.38, 95% CI: 1.38–4.12), rs1256142 (GA vs.GG: aOR = 1.57, 95% CI: 1.01–2.45) and rs11849530 (GG vs. AA: aOR = 1.68, 95% CI: 1.02–2.77) were significantly associated with higher risk of CHD. However, we did not observe a significant association between maternal MTHFD1 rs2236225 and offspring CHD risk. Furthermore, we found the different degrees of interaction effects between polymorphisms of the MTHFD1 gene including rs1950902, rs2236222, rs1256142, rs11849530 and rs2236225, and maternal tobacco exposure.

Conclusions

Maternal polymorphisms of MTHFD1 gene, maternal tobacco exposure and their interactions are significantly associated with the risk of CHD in offspring in Han Chinese populations. However, more studies in different ethnic populations with a larger sample and prospective designs are required to confirm our findings.

Trial registration

Registration number: ChiCTR1800016635.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04419-2.

Genetic polymorphisms associated with obesity in the Arab world: a systematic review

BACKGROUND

Obesity, one of the most common chronic health conditions worldwide, is a multifactorial disease caused by complex genetic and environmental interactions. Several association studies have revealed a considerable number of candidate loci for obesity; however, the genotype-phenotype correlations remain unclear. To date, no comprehensive systematic review has been conducted to investigate the genetic risk factors for obesity among Arabs.

OBJECTIVES

This study aimed to systematically review the genetic polymorphisms that are significantly associated with obesity in Arabs.

METHODS

We searched four literature databases (PubMed, Science Direct, Scopus, and Google Scholar) from inception until May 2020 to obtain all reported genetic data related to obesity in Arab populations. Quality assessment and data extraction were performed individually by three investigators.

RESULTS

In total, 59 studies comprising a total of 15,488 cases and 9,760 controls were included in the systematic review. A total of 76 variants located within or near 49 genes were reported to be significantly associated with obesity. Among the 76 variants, two were described as unique to Arabs, as they have not been previously reported in other populations, and 19 were reported to be distinctively associated with obesity in Arabs but not in non-Arab populations.

CONCLUSIONS

There appears to be a unique genetic and clinical susceptibility profile of obesity in Arab patients.

CpG-SNP site methylation regulates allele-specific expression of MTHFD1 gene in type 2 diabetes

The interaction of genetic and epigenetic mechanisms is one of the underlying causes of phenotypic variability in complex diseases such as type 2 diabetes (T2D). To explore the influence of genetic and epigenetic changes in T2D, we examined the effect of methylation of CpG-SNP sites on allele-specific expression (ASE) in one-carbon metabolism pathway genes in T2D. Case-control study was conducted on 860 individuals (430 T2D and 430 controls). CpG-SNPs shortlisted through in silico analysis were genotyped using tetra ARMS PCR and validated using Sanger DNA sequencing. Global DNA methylation was carried out using RP-HPLC. Promoter DNA methylation and CpG site-specific methylation were carried out using bisulfite sequencing. mRNA expression and ASE were examined by SYBR green and TaqMan assay, respectively. Four exonic CpG-SNPs of MTHFD1, MTRR, and GGH genes were identified in folate pathway genes. Among these, MTHFD1 rs2236225 showed significant association with T2D independent of obesity, displayed ASE, and correlated with CpG-SNP site-specific methylation when compared with controls. Our results demonstrate that SNP rs2236225 in the CpG site of MTHFD1, which regulates allele-specific gene expression in PBMCs is methylation dependent and may perturb one-carbon metabolism pathway in T2D subjects.