Answers: E, both A and C - Maple-syrup urine disease (MSUD) is an autosomal recessive disorder in infants caused by the inability of the body to metabolize the branched-chain amino acids leucine, isoleucine, and valine. The failure to break down branched-chain amino acids is due to a gene mutation controlling the activity of the enzyme alpha-ketoacid dehydrogenase. Plasma levels of leucine exceeding 10 mg/dl are associated with the symptoms of MSUD, including lethargy, vomiting, and neurologic changes.
Newborns with MSUD have pee or earwax that smells sweet, like maple syrup. They also may have problems with feeding, vomit, be fussy or irritable, have a high-pitched cry, have a low energy level, and be very sleepy. If a midwife observes these she should escalate to the pediatrician, who may also involve a genetic counselor.
