DOI: 10.6084/m9.figshare.19350232.v1
title: Association of <i>MTHFR</i> 677C &gt; T gene polymorphism with neonatal defects: a meta-analysis of 81444 subjects

description: This meta-analysis was performed to clarify controversial associations of the <i>MTHFR</i> 677<b> </b>C &gt; T gene polymorphism in maternal and foetal tissue with neonatal defects. It was reported the association of <i>MTHFR</i> 677 C &gt; T gene polymorphism with frequencies of neonatal defects including congenital heart disease (CHD), neural tube defects (NTD), non-syndromic cleft lip and palate (NSCL/P), and Down syndrome (DS). Depending on the neonatal defect subtypes, <i>MTHFR</i> 677 C &gt; T gene polymorphism was associated with NTD, CHD (except for codominant mode of inheritance (TC/CC) and dominant mode of inheritance (TT + TC/CC); <i>p</i> = .167 and <i>p</i> = .054, respectively), DS, and NSCL/P (codominant mode of inheritance (TC/CC), <i>p</i> = .032) in the maternal group. However, in the neonatal group, the <i>MTHFR</i> 677 C &gt; T gene polymorphism was only associated with the frequency of NTD and CHD. Maternal and neonatal <i>MTHFR</i> 677 C &gt; T gene polymorphisms appear to be associated with neonatal defects but differ by defect types.IMPACT STATEMENT<b>What is already known on this subject?</b> Neonatal defects are a signifcant problem and are related to genes involved in the metabolism of homocysteine and folate.<b>What do the results of this study add?</b> The <i>MTHFR</i> 677C &gt; T polymorphism in maternal and neonatal subjects was significantly associated with neonatal defects. When the neonatal subjects were stratified based on disease, the maternal <i>MTHFR</i> 677C &gt; T polymorphism was found to be significantly correlated with all four neonatal defects. In contrast, the polymorphism in newborns was significantly associated with neural tube defects.<b>What are the implications of these findings for clinical practice and/or further research?</b> We believe that our study makes a significant contribution to the literature because it collectively analysed neural tube defects, congenital heart disease, cleft lip and palate, and Down syndrome in relation to the 677C &gt; T polymorphism of <i>MTHFR</i>. Thus, we anticipate that this study will serve as a valuable resource for future investigations of neonatal defect prevention and maternal inheritance in newborn diseases. <b>What is already known on this subject?</b> Neonatal defects are a signifcant problem and are related to genes involved in the metabolism of homocysteine and folate. <b>What do the results of this study add?</b> The <i>MTHFR</i> 677C &gt; T polymorphism in maternal and neonatal subjects was significantly associated with neonatal defects. When the neonatal subjects were stratified based on disease, the maternal <i>MTHFR</i> 677C &gt; T polymorphism was found to be significantly correlated with all four neonatal defects. In contrast, the polymorphism in newborns was significantly associated with neural tube defects. <b>What are the implications of these findings for clinical practice and/or further research?</b> We believe that our study makes a significant contribution to the literature because it collectively analysed neural tube defects, congenital heart disease, cleft lip and palate, and Down syndrome in relation to the 677C &gt; T polymorphism of <i>MTHFR</i>. Thus, we anticipate that this study will serve as a valuable resource for future investigations of neonatal defect prevention and maternal inheritance in newborn diseases.