Intestinal disaccharidases in Greenland Eskimos

Jejunal biopsies from 19 adult Greenland Eskimos were studied regarding disaccharidases, two intracellular beta-galactosidases, and morphological appearance. Fifteen of the patients (79%) had low lactase activity, and 3 of these (16%) had sucrase-isomaltase deficiency as well. Two patients had low trehalase activity. Microscopical appearance was essentially normal in all the biopsies, except for a certain stromal plasma cell infiltration. All the patients with low lactase activity had a measurable residual activity of brush border lactase, which was localized in the middle and apical parts of villi, as normally seen for digestive enzymes. Lysosomal acid beta-galactosidase and cytosol hetero beta-galactosidase were not altered. In the patients with sucrase-isomaltase deficiency there was a complete absence of active sucrase-isomaltase complex. The residual maltase, as well as the very weak residual isomaltase, was exerted exclusively by the heat stable maltases (maltase II and III). The material is the first one in which multiple, but not generalized disaccharidase deficiencies are demonstrated.