Knew those genetics courses would come in handy some day. MSUD (Maple sugar urine disease) is a rare (1:200,000), autosomal recessive inborn error of metabolism. THe three amino acids affected are leucine, isoleucine and valine. Symptoms are maple sugar scented urine, seizures and developmental problems. Treatment is restriction of the three amino acids in question. Mature human milk contains from 1 to 6 micromoles/deciliter of these three amino acids. Sounds low to me. You could compare these levels (the individual levels are in Lawrence, p.110) with those in the abm manufactured for this condition. The infant could be monitored for blood levels of leucine, isoleucine and valine, and human milk decreased in favor of a food free of these amino acids, if one exists, until a balance is reached. This is the same way PKU is handled in a breastfed infant. Let us know what else you find out. Catherine Watson Genna, IBCLC NYC [log in to unmask]