In a recent report in the Journal (Amer J Dis Child 106:578-585 [Dec] 1963) the family tree of two babies with maple syrup urine disease was shown. Recently, another infant with MSUD was found in a collateral branch of the family. In the course of establishing the links between the new and older cases, the published pedigree was found to be incorrect. Because of a confusion of surnames, the paternal grandfather of patient Y is shown as the sibling of the maternal great-grandmother of patient X. The correct relationship is shown in the accompanying chart. Because of the similarity of surnames, it is very likely that the four parents have a common progenitor but the fact cannot be established.