Selective screening for inherited metabolic disorders in a tertiary care hospital of Karachi - A retrospective chart review

Background & Objective: Selective high-risk screening of children suspected of having inherited metabolic disorders was conducted jointly by Chemical Pathology section and the Pediatric Department of Indus Hospital and Health Network- (IHHN) from October 2020-March 2022. Tandem mass spectrometry (MS) for newborn screening was recently introduced in a local laboratory. We did a selective high screening of children for metabolic disorders by using MS for neonates and other relevant tests for older children in our hospital. The present study was undertaken to get an estimate of the number of metabolic cases screened and identified after inclusion of an extended workup. Methods: This is a retrospective chart review of children who were selectively screened for IMDs. Patients' records with ages ranging from birth to fourteen years of age were retrieved from the electronic records department of IHHN from October 2020 to March 2022. Records were searched for demographic data, history, signs, symptoms, and lab investigations. All relevant information was recorded on a pre-designed questionnaire. Results: A total of 178 children were screened for inherited metabolic disorders. Majority of the children screened were less than one month of age 96 (54%). Consanguinity was noted in 74 (41.5%) children. Most common symptoms observed were failure to thrive in 77 children (43%), hypoglycemia in 45 children (25%), and feeding difficulty in 36 children (20%). Inherited metabolic disorders were confirmed in 12 children out of which five had congenital adrenal hyperplasia, four had cystic fibrosis and three children had congenital hypothyroidism. Conclusion: In the present study, we were able to screen several children after inclusion of an extended metabolic workup. However, confirmation of many disorders like fatty acid oxidation defects, disorders of carbohydrate metabolism, and sphingolipidosis could not be done due to lack of confirmatory tests. We recommend that confirmatory tests of these disorders be included in local labs.