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A newborn vomits after each feeding of milk-based formula, and does not gain weight. Biochemical testing
reveals a severe deficiency of galactose-1-phosphate uridyltransferase, consistent with homozygosity.
If this condition goes untreated, what is the likely outcome for this patient?
A. Benign disease except for cataract formation
B. Chronic emphysema appearing in early adulthood
C. Chronic renal failure appearing in adolescence
D. Death in infancy
E. Gastrointestinal symptoms that remit with puberty
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i guess no body wants to try this one
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The correct answer is D. Galactosemia occurs in two very different clinical forms. Deficiency of
galactokinase produces very mild disease with the only significant complication being cataract
formation. In contrast, homozygous deficiency of galactose-1-phosphate uridyltransferase produces
severe disease culminating in death in infancy. In addition to galactosemia and galactosuria, these
patients have impaired renal tubular resorption leading to aminoaciduria, gastrointestinal symptoms,
hepatosplenomegaly, cataracts, bleeding diathesis, hypoglycemia, and mental retardation.
Pathologically, the CNS shows neuronal loss and gliosis and the liver shows fatty change progressing
to cirrhosis.
Benign disease with cataract formation (choice A) is characteristic of galactokinase deficiency.
Chronic emphysema (choice B) is not associated with homozygous galactose-1-phosphate
uridyltransferase deficiency, but rather with alpha 1-antitrypsin deficiency.
Impaired tubular reabsorption (producing aminoaciduria) is seen within a few days or weeks of
feeding milk to an infant with severe galactosemia, as opposed to chronic renal failure appearing in
adolescence (choice C).
Gastrointestinal symptoms (choice E) certainly occur in homozygous galactose-1-phosphate
uridyltransferase deficiency, but they would not be expected to remit with puberty. Instead, most
untreated infants with this disorder show failure to thrive and die in infancy from wasting and
inanition.
