Three patients with new mutations in the EPCAM variant gene for congenital tufting enteropathy and a mutation review in China: a case report.

Background: Congenital tufting enteropathy (CTE) is a rare cause of intractable congenital diarrhea in children, always resulting in parenteral nutrition (PN) dependency. We aimed to report novel mutations in Chinese patients and to illustrate the clinical, histopathological, and molecular features of CTE in China.

Case description: We report three cases of CTE diagnosed with whole-exome sequencing (WES) and MOC31 [a monoclonal antibody of epithelial cell adhesion molecule (EPCAM)] immunohistochemistry. The main manifestations in the three patients were watery diarrhea and growth retardation. Upper endoscopy in three patients revealed villous atrophy of the duodenal mucosa. Histological examination revealed villus abnormalities and two patients with focal tufting. All of the three patients revealed a complete absence of EPCAM expression through MOC31 immunohistochemistry. Five novel mutations, including c.319delG, c.505_507delGAG, c.491+1G>C, c.60del (p.F20Lfs*17), and c.353G>A, in EPCAM were identified through molecular analysis. In our review, there were 18 different mutations in 11 patients from nine studies, with 12 mutations reported only once. In China, 73% of the patients were compound heterozygotes, and most of the pathogenic variants were in exon 3. All patients presented with congenital diarrhea and needed PN because of growth retardation, even when diarrhea was improved. Of the 11 patients, 3 (27%) died.

Conclusions: CTE is rare and fatal, and lacks characteristic changes during endoscopy. Patients with CTE require early diagnosis via histological examination and genetic detection to improve survival.