Congenital Rare Diseases Causing Persistent Diarrhea in the Newborn: A Single Center Experience.

Congenital diarrheal disorders (CDDs) are a heterogeneous group of inherited diseases that typically occur in the first weeks of life or can present later in life after the introduction of different nutrients; they can cause life-threatening severe dehydration and electrolyte disturbances. This study was conducted to characterize the causes of monogenic CDDs, and their clinical consequences. Clinical characteristics of 31 patients with CDDs that occurred in the first month of life and lasted more than 2 weeks were analyzed retrospectively. The patients were divided into groups according to the current CDD classification. The rate of consanguinity among parents was 77.4%. Of the patients, 16 (51.6%) were female and 15 (48.4%) were male. The underlying genetic defect was determined in 26 (83.9%) patients. The most common etiologic factors were digestive disorders of food and absorption and transport of electrolytes (58.1%, 18/31) (most of them being carbohydrate malabsorption disorders, 12/18) and intestinal immune system disorders (9.6%, 3/31). Total parenteral nutrition (TPN) was given to 45.2% (14/31) of the patients. Mortality rate was 28.5% (8/28). In conclusion, early diagnosis and treatment of CDDs with high morbidity and mortality is extremely important in terms of prognosis. Clinical and laboratory findings, stool characteristics, histopathological findings and the effects of dietary therapy are the primary and most important steps that lead to accurate diagnosis. In addition, advanced diagnostic possibilities, including genetic analyses, are essential for diagnosing underlying diseases.