Journal of Clinical Pediatrics ›› 2024, Vol. 42 ›› Issue (9): 798-804.doi: 10.12372/jcp.2024.24e0263

• Original Article • Previous Articles     Next Articles

Megacystis-microcolon-intestinal hypoperistalsis syndrome caused by MYH11 elongating mutation : a case report and literatures review

ZHOU Jie1, LIU Keqiang1,2,3, WANG Jinling1, WANG Ying1,2,3()   

  1. 1. Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University
    2. Shanghai Institute for Pediatric Research
    3. Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai 200092, China
  • Received:2024-03-26 Online:2024-09-15 Published:2024-09-04

Abstract:

Objective To report the clinical characteristics and genetic variant of a patient with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) and to investigate the genotypic-phenotypic correlation through literatures review. Methods The clinical data of a MMIHS child who came to our hospital in October 2023 due to "repeated abdominal distension and vomiting for more than 3 years" were analyzed. Peripheral blood samples were collected from the patient, his parents and his older sister, and the pathogenic mutation was screened by Trio-WES and Sanger sequencing. Relevant literature was summarized and analyzed. Results The patient, a 15-year-old boy, presented with recurrent episodes of abdominal distension, vomiting, and abdominal pain. Abdominal X-ray and upper gastrointestinal contrast study indicated intestinal obstruction. The condition stabilized after treatment with enema, anti-infection and intravenous nutritional support. Genetic testing revealed a heterozygous mutation in the MYH11 gene, identified as c.5819delC (p.Pro1940Hisfs*91), which resulted in the extension of the C-end of the myosin heavy chain and was not detected by either parent or sister. A total of 7 articles related to MYH11 gene mutation were included in the literature review. Mutation types included missense mutations, frameshift mutations, and chromosomal microdeletion. Gender was undetermined in 2 out of 20 patients due to early termination of pregnancy. Among the remaining patients, the male-to-female ratio was 2:1. Genotypic-phenotypic correlation analysis found that 15 patients with dominant heterozygous protein‐elongating MYH11 variants were aged 9 (0-28) years at onset, and no deaths were reported. Five patients with recessive loss-of-function mutations had an onset age of less than 1 year, with 4 deaths (80%). Conclusion This MMIHS patient carries the MYH11 gene c.5819delC (p. Pro1940Hisfs*91) mutation. Compared with patients with MYH11 gene mutation recessive inheritance, those with dominant MYH11 mutations tend to have a later onset, milder clinical manifestations, and a higher survival rate.

Key words: megacystis-microcolon-intestinal hypoperistalsis syndrome, MYH11 gene, child