About Us

The Laboratory for Inborn Errors of Metabolism at the School for Biochemistry, North-West University, Potchefstroom is the only diagnostic laboratory of its kind in South Africa, where screening for metabolic diseases is performed. Since 1983, material of more than 20 000 babies, infants, children and adults were examined for possible metabolic defects.

Patient’s material (urine, cerebrospinal fluid, serum, and fibroblast skin cultures) are referred by pediatricians and doctors from specializing facilities, as well as state institutions in South Africa, to our laboratory for specialized analyses.

Clinicians from Kenya, Namibia and Mauritius also refer patient’s material to our laboratory for the screening of metabolic disorders.

This include neonatal screening assays on blood card samples (done by the neonatal screening laboratory) and confirming assays for abnormalities detected AS WELL AS assays on material of patients with a clinical picture which could fit in with the possibility of a metabolic disorder.

The Potchefstroom Laboratory for Inborn Errors of Metabolism collaborates with internationally acclaimed laboratories in the Netherlands, Sweden, Belgium, Australia and the USA. Development of sensitive and effective techniques in the last few years has enhanced the ability of presenting fast and quality assured results.

The diagnosis of inborn errors of metabolism may stay undetected or delayed in some cases. Presentation can occur at any time, even in adulthood.    Metabolic defects are more prominent in certain areas of the world, for instance in the USA where 1 in 5000 births may have a metabolic error of some sort. The frequency of an individual disease varies based on gender as well as racial and ethnic composition of a population. Successful emergency treatment aims to stabilize the defective metabolism with effective treatment and therapy. (Weiner. 2001: 1)

Single gene defects result in defective anabolism and catabolism of proteins, single amino acids, carbohydrates and fats. Some single gene defects also result in defective transportation of biological molecules and structural abnormalities. Different metabolic error categories can be distinguished in the field of biochemistry. The most prominent and well known categories are defective amino acid metabolism (e.g. PKU), organic acidurias (methylmalonic aciduria), carbohydrate (e.g. galactosemia) and mucopolysaccharidosis defects, errors in the fatty acid metabolism (oxidation, peroxisomal, biosynthesis), defect in the ureum cycle (e.g. OTC) as well as purine and pyrimidine metabolism (e.g. Lesh-Nyhan syndrome). Metabolic errors may also involve more than one part of metabolism, thus called a multi-systemic defect.

Abnormalities may not be detected in the early stages of the disease due to the metabolism adaptation after birth. Common physical abnormalities may include failure to thrive, dysmorphic features, multiple or partial organ failure and abnormalities in the hair, skin and skeleton. In some cases the patients are mentally impaired and developmental delays also occur. Symptoms may be life-threatening (LCAD without l-carnitine treatment) or transient (Vitamin B responsive Methylmalonic aciduria). Some metabolic disease will only be prominent in stress situations and secondary illness. Ornithine carbamylase deficiency in female may be life-threatening when the patient reaches adulthood.

The outcome of long-term study of the South African population indeed confirms that some metabolic diseases are more prevalent in certain population groups. Propionic and isovaleric acidemia are respectively more prevalent among the Afrikaans speaking patients while PKU occurs more frequently among the English speaking patients. Patients with the defects tyrosinemia, MSUD and especially galactosemia, are more prevalent in the non-white population. Diagnosis of cystinuria in adult patients has been prominent in the last 4 years. The occurrence of permanent or transient methylmalonic aciduria due to enzyme or cofactor (Vit B12) defect has also been detected. Ornithine transcarbamylase (OTC) is prominent in Caucasian families. OTC-defects are fatal for the male patient.

A wide range of analysis is used in the investigation of metabolic disease. Organic acids and Amino acids are analysed with a GC-MS and a high quality library is used to identify every compound on the chromatogram. The carnitine levels of patients are analysed by highly sensitive Tandem-MS equipment. Carbohydrates are examined with the help of thin layer chromatography. Mucopolysaccharide defects are identified with gel electrophoresis. Cystine and homocystine analysis are done on an LC-MS-MS. Standardized screening test (e.g. labstix) are also applied in the lab to investigate the complete metabolic profile of every patient. Analyzing urine samples (frozen, on ice) will give the most accurate state of a patient metabolism, but serum (frozen, on ice), CSF (frozen, on ice) and blood cards (air-dried) may also be necessary in the determination of some profiles.