In the Observation titled “Beneficial Prenatal Levodopa Therapy in Autosomal Recessive Guanosine Triphosphate Cyclohydrolase 1 Deficiency,” published in the August 2012 issue (2012;69[8]:1071-1075. doi:10.1001/archneurol.2012.104), there was an error in the text. On page 1072, the fourth sentence under “Patient 2” should have read, “The mother agreed to a prenatal replacement therapy with levodopa/carbidopa, 25%, and started with 50/12.5 mg 3 times a day in week 18.” This article was corrected online.