Screening Urinary Methylmalonic Acid by Thin Layer chromatography in children with Suspected inborn Errors of Metabolism

Introduction: Inborn errors of metabolism (IEM) are a group of disorders due to deficiency of the enzyme. The symptoms are due to the accumulation of toxic substances or deficiency of products. Organic aciduria is a group of IEM which is due to errors in the metabolism of branched chain amino acids and lysine. Studies showed that methylmalonicaciduria (MMA), glutaric aciduria, branched chain aminoacidurias are more common organicaciduria. Many methods are used for detection of methylmalonic acid some of them are not affordable by developing countries. Objective: To study the role of thin layer chromatography in detection of methylmalonic aciduria in children with suspected inborn errors of metabolism. Method: Untimed urine samples were collected from 385 children with clinically suspected inborn errors of metabolism and analyzed for MMA by colour reaction and thin layer chromatography (TLC). Bromocresol green and Ortho dianisidine were the dye used for spotting MMA on TLC. Result: Among 385 children who presented with developmental delay, seizures, hypotonia were worked up for underlying inborn errors of metabolism. Of them 52 children showed positive result for MMA by thin layer chromatography. Discussion: Significant number of children showed positive result for MMA by thin layer chromatography hence the method may be useful for screening methylmalonicaciduria. Further studies required to confirm the diagnosis