Xiong Xiaoyu, Li Jing, Liu Chengjun, Xu Feng
Department of Pediatric Intensive Care Unit, Chongqing Medical University Affiliated Children's Hospital; National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Key Laboratory of Pediatrics, Chongqing, China.
Transl Pediatr. 2021 Mar;10(3):679-685. doi: 10.21037/tp-20-316.
Visceral myopathy is a rare genetic disorder that commonly affects the digestive and renal systems. Manifestations include a clinical spectrum covering chronic intestinal pseudo-obstruction (CIPO) and megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). The smooth muscle actin γ-2 gene () is one of the most common disease-causing genes. Here, we present a case of pediatric intestinal pseudo-obstruction associated with a novel missense mutation, c.588G>C/p.E196D. His parents had no this mutation, which suggested the possibility of spontaneous mutation. Amino acid conservation analysis of γ-2 actin showed replacement of glutamate at position 196 by aspartate. The patient suffered from recurrent episodes of abdominal bloating, undergone repeated gastrointestinal surgery, had feeding difficulties, and required long-term parenteral nutrition support. The patient had no other specific symptoms or underlying diseases. X-ray of the abdomen showed dilation of the intestine as well as an air-fluid pattern. The manifestations of biopsy were various. All biochemical tests were normal, and the possibility of secondary intestinal pseudo-obstruction was excluded. The mutation site of in the present study has not been previously described in patients with visceral myopathy, and thus, our study reveals a novel mutation of -associated visceral myopathy in a patient with CIPO. This report can serve as a reference for future research and further expands the map of genetic variation for visceral myopathy.
内脏肌病是一种罕见的遗传性疾病，通常影响消化系统和肾脏系统。其表现包括一系列临床症状，涵盖慢性肠假性梗阻（CIPO）和巨膀胱-小结肠-肠蠕动减弱综合征（MMIHS）。平滑肌肌动蛋白γ-2基因（）是最常见的致病基因之一。在此，我们报告一例与新型错义突变c.588G>C/p.E196D相关的小儿肠假性梗阻病例。其父母无此突变，提示存在自发突变的可能性。γ-2肌动蛋白的氨基酸保守性分析显示第196位的谷氨酸被天冬氨酸取代。该患者反复出现腹胀发作，接受了多次胃肠道手术，存在喂养困难，需要长期肠外营养支持。患者无其他特异性症状或基础疾病。腹部X线显示肠道扩张以及气液平面。活检表现多样。所有生化检查均正常，排除了继发性肠假性梗阻的可能性。本研究中基因的突变位点此前在内脏肌病患者中未见报道，因此，我们的研究揭示了一例CIPO患者中与基因相关的内脏肌病的新型突变。本报告可为未来研究提供参考，并进一步扩展内脏肌病的基因变异图谱。
