A 3-year-old girl has been a fussy eater since being weaned, particularly when fruit is part of her diet. She would get cranky, sweat, and display dizziness, and lethargy, after eating a meal with fruit. Her mother noticed this correlation, and as long as fruit was withdrawn from her diet, the child did not display such symptoms. The problems the girl exhibits when eating fruit is most likely due to which one of the following?
The patient has HFI, which is caused by a mutation in aldolase B. Sucrose would still be cleaved by sucrase; thus, it would not increase in the stool. Fructose would not be metabolized normally; therefore, it would be elevated in the blood and urine. Aldolase B would not cleave fructose-1-phosphate; thus, its levels would be elevated, and the product, glyceraldehyde, would not be produced.
Decreased levels of fructose in the blood
Elevated levels of glyceraldehyde in liver cells
High levels of sucrose in the stool
Elevated levels of fructose-1-phosphate in liver cells
Carbohydrates