Early onset congenital diarrheas; single center experience.

Background: Congenital diarrheal disorders (CDDs) are a rare group of enteropathies that typically present in the early few months of life and pose a diagnostic challenge. We aimed to analyze the clinical findings and outcome of infants with CDDs and share experience about genetic testing.

Methods: Demographic, clinical and genetic findings, and outcome of the patients (n = 24) with CDDs were recorded from hospital files.

Results: The onset of diarrhea was within the neonatal period in 45.8% of the patients. The most frequent causes of CDDs were defects in digestion, absorption and transport of nutrients and electrolytes (DATN) (n = 11, 45.8%) and defects in intestinal immune-related homeostasis (IIH) (n = 6, 25%). Fat malabsorption (n = 6) was the leading cause of defects in DATN. Extraintestinal manifestations including neurological involvement (25%) and renal involvement (20.8%) were common among the patients. Genetic analyses were performed for 16 patients (targeted gene analysis in 9, congenital diarrhea panel in 3, immune deficiency panel in 1 and whole-exome sequencing in 3 patients). Genetic diagnosis was achieved in 14 of 16 patients (87.5%) with therapeutic consequences in 8 of 16 patients (50%). During the follow-up, 6 patients (25%) died.

Conclusion: The percentage of undefined etiology decreased, and treatment of the patients improved with the increased number of genetic testing in patients with CDDs.