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.