sentence: Phenylketonuria now causes few cases of mental retardation.
sentences_before: In the case of a chemical deficiency, the problem may be curable. For example, phenylketonuria was a cause of mental retardation. Doctors came up with a simple test to find which babies have this condition. They found that if these children got treated and followed a strict diet, they could get enough of the chemical they needed.
concept_name: Phenylketonuria
headings: Birth defect Genetic defects Lethal or damaging genes
categories: Health problems