This study will determine if a non-invasive skin stripping technique can be used to detect individuals with phenylalanine abnormalities, and to monitor dietary and/or drug effects over time. To do this 50 children and adults with phenylalanine abnormalities and up to 50 unaffected controls will be recruited to this study. The 50 affected individuals will have their metabolomic profile analyzed from up to 3 skin-stripping samples over time and compared to their serum amino acid profile in both dried blood spots and a typical blood sample. The unaffected controls will provide one skin-stripping sample. Clinical data regarding compliance with dietary therapy and other medications will be collected to determine other effects on the metabolome.
PURPOSE OF STUDY: To determine if a non-invasive skin stripping technique can be used to detect individuals with phenylalanine abnormalities, and to monitor dietary and/or drug effects over time.