Congenital diarrhea in a newborn infant: A case report

Successful therapy for congenital sodium diarrhea by enteral management: A case report

BACKGROUND

Congenital sodium diarrhea (CSD) is a rare disorder causing electrolyte imbalances due to excessive diarrhea. In pediatric literature, common practice for treating CSD includes parenteral nutrition (PN) for fluid, nutrient, and electrolyte support through the first year of the patient's life. The aim of this study was to report a neonate who showed common symptoms of CSD, including a distended abdomen, large amounts of clear, yellow fluid draining from the rectum, dehydration, and electrolyte abnormalities.

CASE SUMMARY

A diagnostic gene panel was completed and confirmed heterozygous variant GUCY2C gene associated with autosomal dominant CSD. The infant was initially treated with PN to maintain fluid, nutrient, and electrolyte status, but was subsequently transitioned to full enteral feeds, showing improvement in symptoms. Frequent therapy adjustments were required to maintain appropriate electrolyte levels during the duration of the hospital stay. At discharge, the infant followed an enteral fluid maintenance plan that provided symptomatic control through the first year of life.

CONCLUSION

This case demonstrated the ability to maintain electrolyte levels in a patient through enteral means while avoiding long-term use of intravenous access.

Congenital Diarrhea and Cholestatic Liver Disease: Phenotypic Spectrum Associated with MYO5B Mutations

Myosin Vb (MYO5B) is a motor protein that facilitates protein trafficking and recycling in polarized cells by RAB11- and RAB8-dependent mechanisms. Biallelic MYO5B mutations are identified in the majority of patients with microvillus inclusion disease (MVID). MVID is an intractable diarrhea of infantile onset with characteristic histopathologic findings that requires life-long parenteral nutrition or intestinal transplantation. A large number of such patients eventually develop cholestatic liver disease. Bi-allelic MYO5B mutations are also identified in a subset of patients with predominant early-onset cholestatic liver disease. We present here the compilation of 114 patients with disease-causing MYO5B genotypes, including 44 novel patients as well as 35 novel MYO5B mutations, and an analysis of MYO5B mutations with regard to functional consequences. Our data support the concept that (1) a complete lack of MYO5B protein or early MYO5B truncation causes predominant intestinal disease (MYO5B-MVID), (2) the expression of full-length mutant MYO5B proteins with residual function causes predominant cholestatic liver disease (MYO5B-PFIC), and (3) the expression of mutant MYO5B proteins without residual function causes both intestinal and hepatic disease (MYO5B-MIXED). Genotype-phenotype data are deposited in the existing open MYO5B database in order to improve disease diagnosis, prognosis, and genetic counseling.