About us

lab staff

Who we are

The Laboratory for Inborn Errors of Metabolism (PLIEM) is situated in the Centre for Human Metabonomics (CHM) at the Potchefstroom Campus of the North-West University. The Scientists at the CHM are well known for their expertise and many years of experience in the field of inborn errors of metabolism (IEM) and have provided a diagnostic service to both the public and private health sector since 1983. Read more...

The CHM is an active research contributor to the field of inborn errors of metabolism and has published many papers in peer reviewed journals over the past three decades and also has a formal relationship with the metabolic laboratory of the University of Amsterdam, a world renowned institution in the field of metabolic medicine.

Prof. L.J. Mienie is the head of the laboratory and initiated PLIEM. Prof Mienie and his team of medical scientists specialize in the identification of inherited / congenital metabolic defects, neurotoxicology of zenobiotics and are collaborating authors of various research articles. PLIEM further collaborates with internationally acclaimed laboratories in the Netherlands, Sweden, Belgium, Australia and the USA. Since 1983, national and international (e.g. Kenya, Namibia and Mauritius) paediatricians and physicians refer different specimens of patients (babies, infants, children and adults) with possible genetic disorders, to PLIEM for metabolic screening. The lab also partakes in an international external quality control program for metabolic disorders (ERNDIM), to assure service of the highest quality. The members of the lab take part in international training programs and present their research and knowledge at national and international scientific conferences and CPD lectures.

Various sophisticated techniques and instrumentation are used in the diagnostic processes of identification of various metabolites associated with IEMs. Symptomatic presentation of IEMs are very unpredictable and in some cases non-specific. They can occur at any time from infancy to adulthood. Timely emergency intervention and treatment are paramount in improving the quality of life in these patients. This landmark laboratory has tested more than 24 000 patients to date, of which more than 1 450 have been diagnosed with inborn errors of metabolism. Consequently, this laboratory serves as a reference centre for the diagnosis and treatment of patients with metabolic defects across the entire country. This service has filled a need in South Africa and is growing from strength to strength.

PLIEM is also strongly involved in research areas within the NWU. They contribute to the metabolomics research (Prof Reinecke's students and metabolomic investigations in some metabolic defects e.g. isovaleric acidemia and peroxisomal abnormalities) which are one of the main focus areas in our department. The lab is also busy with method development to investigate additional metabolic disorders, which are currently not tested for in South Africa. One of these developments is the investigation of creatine metabolic disorders. The latter is very significant and important due to a large group of infants presenting with seizures of unknown or unexplainable origin, which can be associated with creatine metabolic disorders. The lab is also currently busy building up a DNA biobank of patients with possible metabolic defects. This may assist further research in novel mutation identification and investigation of frequency of metabolic diseases.

The lab is also involved in the investigation of metabolic status and defects in several animal species including: cheetahs, bovine species, crocodiles and scorpions. This research is done together with other departments within the NWU as well as Pretoria Zoo (Dr Adrian Tordiffe) and assist in the prevention of extinction of some animal species.

What we do

PLIEM offers screening for inborn errors of metabolism and a comprehensive metabolic evaluation complete with diagnosis made by its head & founder Prof. L.J Mienie. See our scope of tests and our collaborators .



1979 –Prof. Mienie started his work on metabolic defects in 1979 as part of his M.Sc., screening over 2000 patients at a psychiatric hospital for metabolic defects.

1983 – PLIEM was founded by Prof. L.J. Mienie at the Potchefstroom University for Christian Higher Education (Now the Potchefstroom campus of the North-West University). In its first year, the laboratory was manned by Prof. Mienie and 3 successful diagnoses were made with a borrowed GC-FID in association with Pretoria University.

1985 – PLIEM acquired its own GC-FID

1987 – End of affiliation with the Pretoria University. PLIEM acquired an amino acid analyzer and diagnosed the first Isovaleric acedemia case to be successfully treated. Read more...

1999 – The Newborn Screening project was established, a subdivision of PLIEM. Visit their site...ext link

2008 – Reaches record number of 4337 samples received for the particular year.

Today – The laboratory boasts with 10 permanent employees and high-tech sensitive equipment. An estimated 60000 patients have been screened to date, and about 10% of which was diagnosed with Inborn Errors of Metabolism. PLIEM collaborates with internationally acclaimed laboratories in the Netherlands, Sweden, Belgium, Australia and the USA. Development of sensitive and effective techniques in the past few years enhanced the ability of presenting fast and quality assured results. We celebrated the laboratory's 30th year anniversary in 2013!


Meet the staff

pliem staff

Clinical Pathologist

Prof Chris Vorster

Prof. Chris Vorster is the director of the Centre for Human Metabolomics and the clinical pathologist overseeing result interpretation and diagnostics at PLIEM and NBS.

Consultant & Manager

Dr Marli Dercksen

Dr. Marli Dercksen is the manager of PLIEM and has a Ph.D. in Biochemistry (obtained from the University of Amsterdam). She is responsible for the reporting and verification of results.


Prof. L.J. Mienie

Prof. L.J. Mienie (Japie) is the founder of the laboratory. Prof Mienie specialize in the identification of inherited / congenital metabolic defects, neurotoxicology of zenobiotics and is a collaborating author of various research articles.

The Analysts

Ms Elmarie Davoren

Ms. Elmarie Davoren
M.Sc. in Biochemistry
Head analyst: Acylcarnitine, CDG and organic acid interpretation

Ms Sonja Bartlett

Ms. Sonja Bartlett
Honns. Biochemistry
Head analyst: Screening and MPS assays

Mr Jano Jacobs

Mr. Jano Jacobs
Honns. Biochemistry
Head analyst: Organic acids
& creatinine determination.

Ms Yolanda Nel

Ms. Yolanda Nel
Honns. Biochemistry
Head analyst: Amino acid & VLCFA assays and interpretation

The Administration

Mrs Ansie Mienie

Mrs. Ansie Mienie
B.Bibl (Ed), B.Ed (Hons), M.Ed (Sosio-Pedagogics)
Senior laboratory administrator

Mrs Retha Potgieter

Mrs. Retha Potgieter
B.Sc. Limnology
Administrative assistant.





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