Periconceptional folic acid supplementation can reduce the risk of inborn malformations, including orofacial clefts. Polymorphisms of MTHFR, TCN2, and CBS folate-related genes seem to modulate the risk of cleft lip with or without cleft palate (CL/P) in some populations. CL/P and cleft palate only (CPO) are different malformations that share several features and possibly etiological causes. In the present investigation, we conducted a family-based, candidate gene association study of non-syndromic CPO. Three single nucleotide polymorphisms, namely, rs1801133 of MTHFR, rs1801198 of TCN2, and rs4920037 of CBS, were investigated in a sample that included 129 Italian and 65 Asian families. No evidence of association between the three genotyped polymorphisms and CPO was found in the Italian and Asian cases, indeed the transmission disequilibrium test did not detect any asymmetry of transmission of alleles. This investigation, although with some limitation, further supports that CL/P and CPO diverge in their genetic background.

中文翻译：

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非综合征性left裂：亚洲和意大利人群中叶酸途径的三种基因多态性的关联分析。

围孕期补充叶酸可降低先天性畸形（包括口唇裂）的风险。MTHFR，TCN2和CBS叶酸相关基因的多态性似乎可以调节某些人群中有或没有c裂（CL / P）的唇裂风险。CL / P和仅c裂（CPO）是不同的畸形，具有一些特征和可能的病因。在目前的调查中，我们进行了基于家庭的非综合征性CPO候选基因关联研究。在一个包括129个意大利家庭和65个亚洲家庭的样本中，研究了三个单核苷酸多态性，即MTHFR的rs1801133，TCN2的rs1801198和CBS的rs4920037。在意大利和亚洲的病例中，没有发现这三种基因型多态性与CPO相关的证据，的确，传输不平衡测试没有检测到等位基因传输的任何不对称性。尽管有一定的局限性，但这项研究进一步支持了CL / P和CPO在遗传背景上的差异。