Congenital Sucrase-Isomaltase Deficiency

Abstract

Observations over a period of 6 years are reported on 10 children in whom the diagnosis of congenital sucrase isomaltase deficiency (SID) was confirmed by quantitative estimation of disaccharidase activity of the small intestinal mucosa. Repeat biopsies were performed on eight of the ten patients and showed no evidence that sucrase isomaltase activity is acquired. Sucrose tolerance tests (2 gm/kg) showed no significant rise in blood glucose in the seven patients in whom they were performed. This condition may appear in young infants with severe diarrhea resulting in a malabsorption syndrome and failure to thrive. It may also be manifest in a milder clinical presentation with bothersome diarrhea in spite of normal growth and development in the older infant or young child. The diagnosis in this latter group can be difficult, and is frequently missed.

Congenital Sucrase‐Isomaltase Deficiency

“…Patients with CSID experience vomiting, osmotic diarrhea, mild steatorrhea, chronic diarrhea, and crying spells upon ingestion of sugars (17). Occasionally dehydration, failure to thrive, developmental retardation, and muscular hypotonia were observed, which were compatible with broad clinical heterogeneity (13,18). CSID also has been reported to be associated with nephrocalcinosis, renal calculi, metabolic acidosis, and hypercalcemia (19,20).…”

Congenital Sucrase‐Isomaltase Deficiency

“…In onl y two instances is there a famil y history, with two affected sisters and a father and so n among th e group studied. Chronic watery diarrhea and failu re to thrive are common findings in infants and toddl ers (63). Other nonspecific finding s in this age group include abdominal distenti on , gassiness, colic, irrit abilit y, ex coriated buttock s , diaper rash , and (at time s) vomiting.…”

“…CSID has been diagnosed in adult patients (58,68,69). Many adults with CS ID give a history of feeding difficulties during th eir infa ncy and intermittent symptoms since childhood (58,63) . Occasionally, th e sy mptoms appear as lat e as the time of puberty (69).…”

Sucrase‐isomaltase Gene Variants in Patients With Abnormal Sucrase Activity and Functional Gastrointestinal Disorders

“…The underlying causes of impaired sucrase-isomaltase (SI) activities are pathogenic mutations in the SI gene (2,3,5,(7)(8)(9).…”