Synonym: familial microvillus atrophy, congenital microvillus atrophy, Davidson's syndrome
Inheritance: autosomal recessive. A family history of similarly affected siblings may be helpful for diagnosis.
Clinical features:
(1) onset of a severe, very watery diarrhea soon after birth
(2) dehydration and malabsorption occur quickly
(3) Infants require continuous parenteral nutrition or intestinal transplantation.
Laboratory findings:
(1) fecal sodium and chloride similar to serum concentrations
(2) stool cultures are negative for enteric pathogens
Histologic findings on small bowel biopsy:
(1) hypoplastic villous atrophy with little crypt hyperplasia
(2) absence of a marked inflammatory cell infiltrate
(3) luminal enterocytes are piled-up, disorganized and lack a brush border
(4) PAS positive cytoplasmic inclusions in enterocytes
(5) The cytoplasmic inclusions are positive for immunostains against villin, CEA and CD10.
(6) Electron microscopy show the inclusions to be lined by the microvilli that normally form the brush border on the luminal surface.
