Congenital sucrase-isomaltase deficiency presenting with failure to thrive, hypercalcemia, and nephrocalcinosis.
BACKGROUND
Disaccharide Intolerance Type I (Mendelian Interance in Man database: *222900) is a rare inborn error of metabolism resulting from mutation in sucrase-isomaltase (Enzyme Catalyzed 3.2.1.48). Usually, infants with SI deficiency come to attention because of chronic diarrhea and nutritional evidence of malabsorption.


METHODS
We describe an atypical presentation of this disorder in a 10-month-old infant. In addition to chronic diarrhea, the child displayed severe and chronic hypercalcemia, the evaluation of which was negative. An apparently coincidental right orbital hemangioma was detected. Following identification of the SI deficiency, an appropriately sucrose-restricted, but normal calcium diet regimen was instituted which led to cessation of diarrhea, substantial weight gain, and resolution of hypercalcemia.


CONCLUSIONS
This case illustrates that, similar to congenital lactase deficiency (Mendelian Interance in Man database: *223000, Alactasia, Hereditary Disaccharide Intolerance Type II), hypercalcemia may complicate neonatal Sucrase-Isomaltase deficiency. Hypercalcemia in the presence of chronic diarrhea should suggest disaccharide intolerance in young infants.
Belmont
John W
JW
Department of Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA. jbelmont@bcm.tmc.edu
Reid
Barbara
B
Taylor
William
W
Baker
Susan S
SS
Moore
Warren H
WH
Morriss
Michael C
MC
Podrebarac
Susan M
SM
Glass
Nancy
N
Schwartz
I David
ID
D002118:Calcium / Q000097:blood*; D002239:Carbohydrate Metabolism, Inborn Errors / Q000175:diagnosis*; D005183:Failure to Thrive / Q000209:etiology*; D005260:Female; D006801:Humans; D007223:Infant; D009397:Nephrocalcinosis / Q000209:etiology*; D013394:Sucrase-Isomaltase Complex / Q000172:deficiency*; D013395:Sucrose / Q000378:metabolism*
D013395:Sucrose; D013394:Sucrase-Isomaltase Complex; D002118:Calcium