Sucrase-Isomaltase Deficiency

Abstract

To the Editor: Using a specific rabbit antiserum against pure human sucrase-isomaltase, Gray et al. showed absence of cross-reacting material in all of seven patients affected by congenital sucrase-isomaltase deficiency, including two with residual activity (N Engl J Med 294:750–753, 1976). This finding is coincident with what Preiser et al.¹ and we² have found with use of gel electrophoresis of sodium-dodecyl-sulfate-solubilized microvillus-membrane proteins, but is contradictory to the finding by Dubs et al.³ that variable amounts of inactive enzyme protein could be demonstrated in six other patients.The authors state that "they found no evidence for a cross-reacting protein . . .