Congenital chloride diarrhea
Congenital chloride diarrhea is a genetic disorder due to an autosomal recessive mutation on chromosome 7. The mutation is in downregulated-in-adenoma, a gene that encodes a membrane protein of intestinal cells. The protein belongs to the solute carrier 26 family of membrane transport proteins. More than 20 mutations in the gene are known to date. A rare disease, CCD occurs in all parts of the world but is more common in some populations with genetic founder effects, most notably in Finland.
Symptoms and signs
Chronic diarrhoea starting from early neonatal period. Failure to thrive is usually accompanying diarrhea.Pathophysiology
CCD causes persistent secretory diarrhea. In a fetus, it leads to polyhydramnios and premature birth. Immediately after birth, it leads to dehydration, hypoelectrolytemia, hyperbilirubinemia, abdominal distention, and failure to thrive.Diagnosis
CCD may be detectable on prenatal ultrasound. After birth, signs in affected babies typically are abdominal distension, visible peristalsis, and watery stools persistent from birth that show chloride loss of more than 90 mmol/L.An important feature in this diarrhea that helps in the diagnosis, is that it is the only type of diarrhea that causes metabolic alkalosis rather than metabolic acidosis.