Specific Disaccharidase Deficiency in Adults

Glucose-galactose malabsorption. This rare genetically determined syndrome is at fust sight difficult to correlate with any hypothesis that there is more than one mechanism for glucose transfer, but several explanations are possible. First, in subjects with this condition the absorption of galactose is undetectable but small amounts of glucose are still absorbed (Meeuwisse & Melin, 1969). Secondly, two systems may be determined by a single gene (as is sucrase-isomaltase deficiency). Thirdly, it is possible that one of two systems is frequently absent producing no or only mild symptoms and severe symptoms occur when both are absent simultaneously. Conclusions. There is evidence in vivo that there are two (or more) systems for glucose transport, only one of which is shared with galactose. They are probably present in different ratios in the jejunum and ileum. The two mechanisms emerging from studies in vivo do not readily coincide with observations in vitro.