Abstract: Objective　To improve the understanding of microvilli inclusion disease（MVID） . Methods　Summarize the clinical data of one child with MVID who was diagnosed by multidisciplinary consultation in the Center for Rare Diseases of Beijing Children’s Hospital，Capital Medical University，National Center for Children’s Health in April 2021, and review the literature. Results　The clinical manifestations of MVID were severe watery diarrhea， repeated metabolic acidosis and feeding intolerance. Pathological examination of intestinal villi showed that wellarranged inclusion bodies of microvilli in the cytoplasm of atrophic villi，PAS staining（+），immunohistochemistry of CD10（+），homozygous or complex heterozygous mutation of MYO5B gene were helpful for diagnosis，and the mutation spectrum of MYO5B gene was also extended by this case. This disease needs long-term intravenous nutrition and life support，prevention and treatment of infection and other symptomatic treatment. Cocktail therapy was still in the clinical trial stage internationally, and the effect was not clear. Conclusion　MVID is a rare disease,and the understanding of it should be improved. The early pathological detection of villi based on clinical manifestations and gene test can help to make the diagnosis，but there’s still big challenge in its treatment.

Key words: metabolic acidosis, microvilli inclusion disease, MYO5B gene

摘要： 目的　提高临床对微绒毛包涵体病（MVID）的认识。方法　总结2021年4月经首都医科大学附属北京儿童医院疑难罕见病中心多学科综合会诊确诊的1例MVID患儿临床资料，并复习相关文献。结果　MVID临床表现为严重水样泻、反复代谢性酸中毒及喂养不耐受。小肠绒毛病理检查示小肠绒毛萎缩胞浆内排列整齐的微绒毛构成的包涵体，PAS染色（+）、免疫组化CD10（+），MYO5B基因纯合或复合杂合突变有助于诊断。同时该病例也扩展了MYO5B基因突变谱。该病需长期静脉营养及生命支持、防治感染等对症治疗，鸡尾酒疗法对该病仍处于临床试验阶段，效果不明确。结论　MVID罕见，对于MVID应加强认识，应结合临床表现早期行小肠绒毛病理及基因检测以协助诊断，该病在治疗方面仍存在较大挑战。

关键词: 代谢性酸中毒, 微绒毛包涵体病, MYO5B基因