Extended metabolic screen in sick neonates and children

ABSTRACT

Inborn errors of metabolism [IEM] are rare hereditary diseases resulting from incompetence in enzymatic reactions of intermediary metabolism. They are responsible for a significant level of neonatal and pediatric morbidity and mortality. There are 2 main problems in detecting IEM, first symptoms are non-specific and often similar to those of sick neonates, therefore, only a small number of these diseases will be diagnosed from typical clinical picture alone and we can rarely target the specific investigation required for diagnosis of the offending disease. Secondly, investigations are complex and expensive. In Egypt, with limited facilities, extended metabolic screening [EMS] for sick neonates and children with symptoms indicative of IEM would be the best choice. This approach is called selective screening. In this paper, Extended Metabolic Screen was done to 231 cases [44 neonates and 187 children] with different symptoms suggesting IEM. Abnormal results were found in 22.73% of neonates and in 26.66% of those with previous neonatal death. First cousin marriage was present in 80% of neonates with abnormal EMS. Abnormal screen included organic acidemias [13.63%], amino acid Opathies [4.55%], and fatty acid oxidation defects [4.55%]. On the other hand, 8.56% of children had abnormal results. This included amino acid opathies [5.88%], organic acidemias [1.07%], cystic fibrosis [CF], congenital adrenal hyperplasia [CAH], and congenital hypothyroidism [CH] [1.61%]. We also found that 6.48% of children presenting with mental retardation had phenyl ketonuria [PKU], and nearly 10% of Children presenting with convulsion had MSUD, and another 10% had CAH. To conclude, selective screening to sick neonates and children with a simple, relatively cheap method like Extended Metabolic Screen [EMS] is the best cost effective test with high detection rate for IEM in neonates and children especially in Egypt with both high rate of consanguinity and limited facilities. A national screening program for PKU is extremely essential and increased awareness of the clinical presentation of the disease is a priority