Background
Congenital chloride diarrhea (CCD) is a rare autosomal recessive condition characterized by lifelong watery diarrhea. It is caused by mutations in the SLC26A3 gene on chromosome 7q31, which encodes for Cl-/HCO3 exchanger, leading to its absence and thus Cl-rich watery diarrhea [1,2]. The incidence of CCD has been documented in a range of ethnic populations, such as Finland, Poland, and Saudi Arabia, carrying the same mutation due to the genetic founder effect. Saudi Arabia has a prevalence estimated at around 1:5500, though it may be considerably higher [2,3]. Patients usually present with polyhydramnios and intestinal dilatation, which is detected prenatally, requiring hospitalization and rigorous hydration due to potential complications. Shortly after delivery, patients frequently experience severe diarrhea, which can lead to dehydration and electrolyte imbalances [1,4].
The condition manifests itself by causing hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis [4]. The patient is treated with lifelong salt substitution treatment to prevent dehydration as well as allow average growth and development as the intestinal defect cannot be fixed. In most situations, additional therapies such as butyrate and cholestyramine successfully reduce diarrhea [1-3]. CCD is challenging to diagnose because of its severe clinical presentations and differentials. Therefore, it is crucial to be diagnosed early and receive appropriate management [1]. CCD causes early death if left untreated or due to complications such as impaired renal function, nephrocalcinosis, and end-stage renal disease [1-3]. This case report represents a case of a Saudi newborn boy with CCD and his management.
Case Presentation
A Saudi newborn baby boy who was born in August 2021 with a condition of passing a large amount of urine through the anal canal and was otherwise healthy [Video 1] (Hyperlink: https://youtu.be/uVjN39uTCKw). The baby was born via spontaneous vaginal delivery, full-term, with an average birth weight of 3.1 Kg, passed meconium within the first 24 hours, and uneventful antenatal history. The parents are cousins, and the mother is 30 years old and healthy, with no known medical or genetic illnesses. There is a family history of similar presentation of two siblings at birth who unfortunately did not survive.
Initially, he was admitted to a local hospital with high suspicion of a colovesical fistula, which prompted close monitoring in the neonatal intensive care unit and specialized care to address dehydration and stabilize the infant. The baby was referred to a tertiary center for further pediatric surgical consultation and management. Further investigations and physical examination yielded inconclusive results.
After excluding colovesical fistula and bowel obstruction, blood laboratory tests revealed hyponatremia (124mml/l), hypokalemia (2.5mEq/l), and a pH level was 7.25. Urine analysis was unremarkable. However, stool analysis revealed a high elevation of chloride level (95mmol/l), which confirmed the diagnosis of CCD. The colovesical fistula was excluded and confirmed by the absence of a fistula based on a contrast study. The infant’s management included resuscitation and medical intervention without the need for surgical intervention. The medical team closely monitored the newborn’s hydration status and implemented appropriate electrolyte replacement therapy. The patient responded well to treatment, and the prognosis was favorable.
Discussion
CCD is a rare autosomal recessive disorder characterized by chronic diarrhea due to impaired chloride absorption in the intestines. Diagnosis can be challenging, but early recognition is crucial for effective management and prevention of complications. The reviewed literature sheds light on various aspects of CCD, emphasizing the importance of early diagnosis and management. The literature highlights the significance of a high level of suspicion for CCD in infants presenting with chronic diarrhea, particularly in regions with a high prevalence of consanguineous marriages. Antenatal ultrasound findings, such as dilated bowel loops, can serve as an important diagnostic clue for CCD. This early identification allows for prompt investigations and the initiation of appropriate management strategies to prevent complications [4-7].
A case report and literature review underscored the diagnostic challenges of CCD and its overlaps with other conditions, such as Bartter syndrome and ulcerative colitis. This emphasizes the need for a comprehensive evaluation, including genetic testing, to confirm the diagnosis of CCD and avoid misdiagnosis. Early recognition is vital for preventing serious complications [5]. In addition, the co-occurrence of CCD with other rare genetic disorders, such as pendred syndrome, highlights the complex genetic nature of these conditions. The presence of multiple rare recessive traits in consanguineous couples can increase the risk of CCD in their progeny. Understanding these genetic associations can aid in accurate diagnosis and counseling [8].
The review of CCD’s clinical features and management strategies emphasizes the importance of a multidisciplinary approach and close follow-up. CCD is a multisystemic disorder with heterogeneous complications requiring individualized management. Optimal therapeutic strategies and regular monitoring are essential for improving outcomes and maintaining a good quality of life [1,6-9].
The presentation of the infant passing urine through the anal canal.
Available from: https://youtu.be/uVjN39uTCKw
Conclusion
This case report highlights an unusual presentation of CCD mimicking a colovesical fistula. To the best of our knowledge, no similar case has been reported in the literature, and we believe this is the first Saudi case report with an unusual presentation. It underscored the diagnostic challenges of this rare disorder and emphasized the importance of early recognition and accurate diagnosis to prevent such complications. A multidisciplinary approach and individualized management strategies are essential for optimizing outcomes in CCD patients. Further research and awareness are needed to improve understanding and facilitate timely intervention in atypical CCD presentations.