Genetic investigation confirmed the clinical phenotype of congenital chloride diarrhea in a Hungarian patient: a case report

Congenital chloride diarrhea clinical features and management: a systematic review

INTRODUCTION

Congenital chloride diarrhea (CLD) is a rare autosomal recessive disorder characterized by watery diarrhea with a high level of fecal Cl^-, metabolic alkalosis, and electrolyte alterations. Several intestinal and extraintestinal complications and even death can occur. An optimal knowledge of the clinical features and best therapeutic strategies is mandatory for an effective management.

METHODS

Articles published between 1 January 1965 and 31 December 2019, reported in PUBMED and EMBASE, were evaluated for a systematic review analyzing four categories: anamnestic features, clinical features, management, and follow-up strategies.

RESULTS

Fifty-seven papers reporting information on 193 CLD patients were included. The most common anamnestic features were positive family anamnesis for chronic diarrhea (44.4%), consanguinity (75%), polyhydramnios (98.3%), preterm delivery (78.6%), and failure to pass meconium (60.7%). Mean age at diarrhea onset was 6.63 days. Median diagnostic delay was 60 days. Prenatal diagnosis, based on molecular analysis, was described in 40/172 (23.3%). All patients received NaCl/KCl-substitutive therapy. An improvement of diarrhea during adulthood was reported in 91.3% of cases. Failure to thrive (21.6%) and chronic kidney disease (17.7%) were the most common complications.

CONCLUSIONS

This analysis of a large population suggests the necessity of better strategies for the management of CLD. A close follow-up and a multidisciplinary approach is mandatory to manage this condition characterized by heterogeneous and multisystemic complications.

IMPACT

In this systematic review, we describe data regarding anamnestic features, clinical features, management, and follow-up of CLD patients obtained from the largest population of patients ever described to date. The results of our investigation could provide useful insights for the diagnostic approach and the management of this condition.

Segmental maternal uniparental disomy of chromosome 7q in a patient with congenital chloride diarrhea

Background

The main symptoms of congenital chloride diarrhea (CCD) main symptoms are watery diarrhea, hypochloremia, and hypokalemic metabolic alkalosis. Silver–Russell syndrome (SRS) is a heterogeneous imprinting disorder characterized by severe intrauterine retardation, poor postnatal growth, and facial dysmorphism.

Methods

Parent‐offspring trio whole‐exome sequencing was used to identify the causal variants. Sequencing reads were mapped to the reference of human genome version hg19. Sanger sequencing was performed as a confirmatory experiment.

Results

The proband was a patient with SRS caused by maternal uniparental disomy 7. The CCD of the proband was caused by homozygous variant c.1515–1 (IVS13) G>A; both mutated alleles were inherited from her mother.

Conclusion

We report the first clinical case of CCD and SRS occurring together. Patients with milder phenotypes may be difficult to diagnose in early stage, but close monitoring of potential complications is important for identification.

Prenatal and Postnatal Manifestations of Congenital Chloride Diarrhea Due to a Heterozygote Variant of the SLC26A3 Gene: A Case Report

Congenital chloride diarrhea (CCD) is caused by a recessive mutation in the SLC26A3 gene and characterized mainly by watery diarrhea, hypochloremia and metabolic alkalosis. Various different mutations in SLC26A3 are responsible for the disease. In the prenatal period, the symptoms of CCD may include polyhydramnios, preterm labor and abdominal distension. The main feature of CCD is chloride-rich diarrhea, which leads to excessive loss of fluid and salt immediately after birth and is followed by weight loss and dehydration. Hyponatremia and hypochloremia are soon accompanied by hypokalemia and metabolic alkalosis. Untreated CCD is fatal even in the first weeks of life. Diagnosis is made by high fecal chloride concentrations in patients with serum electrolytes corrected by salt substitution and confirmed using genetic testing of peripheral blood samples. Here, we detail prenatal and postnatal manifestations of a preterm infant, born via Caesarian section, who was suspected to suffer intrauterine bowel obstruction. Upper median laparotomy was performed and no intestinal abnormalities found. The course of the neonatal period was complicated by severe diarrhea with hypochloremia, hyponatremia and metabolic alkalosis. Based on the patient's clinical picture and stool examination, a diagnosis of CCD was established. Mutation of the SLC26A3 gene was confirmed using genetic testing.