A breastfed newborn has just been diagnosed with galactosemia. The therapeutic management for this newborn is to:

Choice A reason:

Stop breastfeeding. This is the correct answer because newborns and infants with galactosemia cannot metabolize galactose, a sugar found in milk and lactose-containing formulas, including breast milk. Galactose can build up in their blood and cause serious complications such as liver damage, cataracts, brain damage, and even death. Therefore, the therapeutic management for this newborn is to stop breastfeeding and switch to a soy or elemental formula that contains no galactose.

Choice B reason:

Add amino acids to the breast milk. This is incorrect because adding amino acids to breast milk will not prevent the accumulation of galactose in the newborn's blood. Amino acids are the building blocks of proteins, not sugars. Adding amino acids to breast milk will not change its galactose content or help the newborn metabolize it.

Choice C reason:

Substitute a lactose-containing formula for breast milk. This is incorrect because lactose is a disaccharide composed of glucose and galactose. Lactose-containing formulas will also expose the newborn to galactose, which they cannot break down. Lactose-containing formulas should be avoided in newborns and infants with galactosemia.

Choice D reason:

Give the appropriate enzyme along with breast milk. This is incorrect because there is no enzyme therapy available for galactosemia. Galactosemia is caused by a genetic defect in one of the enzymes involved in the breakdown of galactose, such as galactose-1-phosphate uridyltransferase (GALT), galactokinase (GALK), or uridine diphosphate galactose-4-epimerase (GALE). Giving an enzyme along with breast milk will not correct this defect or prevent the harmful effects of galactose accumulation.