¹Department of Biochemistry, Faculty of Medicine, Benghazi University;
²Department of Medicine and Critical Care;
³Department of Anatomy and Histology, Faculty of Medicine, Benghazi University; Benghazi, Libya
*Corresponding author: Prof. D.S.Sheriff. Department of Biochemistry, Faculty of Medicine, Benghazi University, Benghazi, Libya; E-mail: email@example.com
Published: September 24, 2013
Inborn errors of metabolism (IEM) are a heterogeneous group of monogenic diseases that affect the metabolic pathways. The detection of IEM relies on a high index of clinical suspicion and co-ordinated access to specialized laboratory services. Biochemical analysis forms the basis of the final confirmed diagnosis in several of these disorders.
The investigations fall into four main categories
- General metabolic screening tests
- Specific metabolite assays
- Enzyme studies
- DNA analysis
The first approach to the diagnosis is by a multi-component analysis of body fluids in clinically selected patients, referred to as metabolic screening tests. These include simple chemical tests in the urine, blood glucose, acid-base profile, lactate, ammonia and liver function tests. The results of these tests can help to suggest known groups of metabolic disorders so that specific metabolites such as amino acids, organic acids, etc. can be estimated. However, not all IEM needs the approach of general screening. Lysosomal, peroxisomal, thyroid and adrenal disorders are suspected mainly on clinical grounds and pertinent diagnostic tests can be performed. The final diagnosis relies on the demonstration of the specific enzyme defect, which can be further confirmed by DNA studies.
- Marsden D, Larson C, Levy HL. Newborn screening for metabolic disorders. J Pediatr 2006; 148(5):577-584.
- David Kronn. Developing Diagnostic Guidelines for Conditions in the Newborn Screening Panel. http://www.aphl.org/conferences/proceedings/Documents/2008%20_APHL_NBS_a...
- Wilcken B, Wiley V, Hammond J, Carpenter K. Screening newborns for inborn errors of metabolism by tandem mass spectrometry. N Engl J Med 2003; 348(23):2304-12.
- Scriver CR, Beaudet AL, Sly WS, Valle D. (eds). The Metabolic and Molecular Bases of Inherited Disease, 8th edn, New York: McGraw-Hill; 2001.
- Jean-Marie Saudubray, Georges van den Berghe, John H. Walter. Inborn Metabolic Diseases: Diagnosis and Treatment. Springer-Verlag, 2012.
The fully formatted PDF version is available.
Int J Biomed. 2013; 3(3):211-214. © 2013 International Medical Research and Development Corporation. All rights reserved.