背景:Hirschsprung病是一种功能性的胃肠道阻塞,原因是先天性在远端肠肌间神经丛缺乏神经节细胞。胃肠运动需要完整的肌肉层以及神经网络连接才能正常运行。肌动蛋白G2基因是编码肌动蛋白γ2的主要基因;在肠组织中发现的平滑肌肌动蛋白。
目的:本研究探讨了一组Hirschsprung病患者肌动蛋白G2基因异常和手术后假性梗阻的可能分子基础。据作者所知,这是首次证实先天性巨结肠的结构性肌肉缺陷的报告。
方法:获得伦理许可和知情同意。从10例经组织学证实的HSCR患者的全血样品中提取DNA。ACTG2基因的PCR扩增,进行半自动双向测序分析。使用FinchTV序列比对软件(http:/en.biosoft.net)读取色谱文件。通过PolyPhen2软件获得了进一步的预测生物信息学调查,以评估所观察到的氨基酸变化的重要性。
结果:前瞻性研究了10名具有相似HSCR表型的新患者的肌动蛋白G2γ基因(ACTG2)变异。ACTG2基因剖析成果显示ACTG2基因外显子5、8和10的变异中有7个(64%)。c.109C>GS345L是最常见的发生在10例患者中的6例(54%),第10外显子的c.171A>AK119E和显著的c.108T>GW357G变异(1例患者)4例患者在不同的外显子中有不同变异的组合,差异不显著。南非人群的对照样本上的等位基因频率没有显示出可比的病理学联系得分(http://gnomad。broadinstitute.org/)。生物信息学计算机建模表明,两个变体(Lys到Glu和Trp到Gly)中的残基置换是高度非保守的,变异可以改变蛋白质构象内的相互作用。
结论:肌动蛋白平滑肌基因在64%的样本中显示出变异,表明许多HSCR患者肌肉功能异常的原因。Hirschsprung疾病是复杂频谱的一部分,其中还包括平滑肌。
方法:VI.
BACKGROUND: Hirschsprung disease is a functional obstruction of the gastrointestinal tract due to the congenital absence of ganglion cells in the intermyenteric plexuses of the distal bowel. Gastrointestinal motility requires intact muscular layers as well as neural network connection to function properly. The Actin G2 gene is the main gene encoding actin gamma 2; a smooth muscle actin found in enteric tissues.
OBJECTIVE: This study of the Actin G2 gene in patients with Hirschsprung disease explores a possible molecular basis abnormal muscle function and post-surgical pseudo-obstruction in a group of patients. As far as the authors are aware, this is the first report confirming structural muscle deficits in Hirschsprung disease.
METHODS: Ethical permission and informed consent were obtained. DNA was extracted from whole blood samples in 10 patients with histologically proven HSCR patients. PCR amplification of the ACTG2 gene, were subjected to semi-automated bi-directional sequencing analysis. Sequencing results were analyzed using FinchTV Sequence Alignment Software (http:/en.biosoft.net) to read chromatogram files. Further predicting bioinformatic investigation was obtained by PolyPhen 2 software to evaluate the significance of the observed amino acid changes.
RESULTS: Ten new patients with similar HSCR phenotypes were prospectively investigated for variation in the Actin G2 gamma gene (ACTG2) variations. The results of ACTG2 gene analysis showing variation in exons 5, 8 and 10 of the ACTG2 gene in 7 of them (64%). The c.109C > G S345 L was the most frequent occurring in 6 of the 10 patients (54%), the c.171 A > A K119E in 2 and the significant c.108 T > G W357G variation in exon 10 (1 patient) Four patients had a combination of different variants in different exons which were less significant. Allele frequency on a control sample of the South African population showed no comparable pathology link scores (http://gnomad.broadinstitute.org/). Bioinformatic in silico modeling showed that the residue replacements in both variants (Lys to Glu and Trp to Gly) are highly non-conservative and variation can alter interactions within the protein conformation.
CONCLUSIONS: The Actin smooth muscle gene showed variation in 64% of samples, indicating a reason for abnormal functioning muscle in many HSCR patients. Hirschsprung disease is part of a complex spectrum which also includes smooth muscle.
METHODS: VI.