The disaccharidase activities in small-intestinal surgical biopsy specimens from 97 Greenlanders were investigated. Five of the patients, or 5%, had sucrase deficiency. The diagnosis, sucrose malabsorption, was established by sucrose tolerance tests. In all parts of the world other than the arctic regions sucrase deficiency is a rare condition. The patients were divided into three separate groups in accordance with their sucrase activity. The middle group was considered to be heterozygote carriers of the sucrase-deficient gene. The number of people in the group corresponded to the theoretical number of heterozygotes in accordance with the Hardy-Weinberg equation, suggesting that sucrase deficiency is recessively inherited in a simple Mendelian fashion. Four of the five patients with sucrase deficiency had deficiency of lactase as well. The nutritional implications are discussed.

Their conclusion was that adults with hypolactasia probably synthesise a decreased amount of lactase protein but the conclusion was in part limited by their procedure, which involves loss of material during the membrane preparation procedure and a possible poor separation of lactase from other unknown proteins.A precise answer whether lactase protein is qualitatively altered in hypolactasia has not yet been given. This had been considered possible by using specific antibodies against the enzyme6 but, because of the great lability of lactase during purification procedures, this has until now not been done.Received for publication 4 September 1979 We have previously described7 quantitative immunoelectrophoresis of proteins from single, unfractionated, small intestinal biopsies against a specific brush border protein antiserum. As the lactase precipitate was identified by enzymatic staining and the analysis determines the amount of immunological reactive protein, the application of this method makes a quantitative approach possible without the limitations of earlier investigations. In the present paper we describe the results of such an investigation on 18 hypolactasia patients and 24 controls. Methods PATIENTS

The Epstein-Barr virus (EBV)-specific antibody profile of 101 Greenland Eskimo children was determined. The proportion of children with serological evidence of recent or past primary EBV infections rose from 22% at 6 months of age to 79% at 24 months of age. All but 2 of 49 children more than 4 years of age proved seropositive. The geometric mean titre (GMT) of antibodies to the viral capsid antigen (VCA) was highest during the first 3 years of life and declined sharply to a lower, nearly constant level in older children. The GMT of antibodies to the nuclear antigen (EBNA), rose slowly during the first 4 years of life to its persistent level. None of the children had a history of illnesses comparable to infectious mononucleosis. The results have shown that in this population with an enhanced risk of nasopharyngeal carcinoma, primary EBV infection occurs at a very early age.

No abstract