Further delineation of SLC9A3-related congenital sodium diarrhea.

Background: Congenital sodium diarrhea (CSD) is a rare enteropathy displaying both broad variability in clinical severity and genetic locus and allelic heterogeneity. Eleven CSD patients were reported so far with SLC9A3 variants that impair the function of the encoded intestinal sodium-proton exchanger 3 (NHE3).

Methods: We report a 4-year-old patient, born prematurely in the 35th week of gestation, with antenatal polyhydramnios and dilated intestinal loops, and with diarrhea of congenital onset, 2-6 times a day, and with polydipsia.