Within recent years the search for metabolic defects responsible for mental retardation has been greatly intensified. Not only have several new inborn errors of metabolism associated with cerebral malfunction been described,1-7 but it has also been possible to detect atypical clinical pictures of previously well-characterized diseases, such as phenylketonuria.8
One factor responsible for this impetus is the increasingly widespread use of paper chromatography as part of the diagnostic armamentarium of the pediatric neurologist. This procedure demands little in terms of time, space, and cost of operation, and offers a method of analysis for a wide diversity of chemical substances. As a consequence, many clinicians have turned to paper chromatography as a means of detecting abnormal metabolites or abnormal quantities of normal intermediary metabolic products.
For the past 3 years, one of us (J.H.M.) has been screening children suffering from a variety of neurological diseases for possible metabolic defects.
MENKES JH, RICHARDSON F, VERPLANCK S. Program for the Detection of Metabolic DiseasesChromatographic Screening to Find Metabolic Diseases, Especially Those Involving the Nervous System. Arch Neurol. 1962;6(6):462–470. doi:10.1001/archneur.1962.00450240040005