The early diagnosis of inherited metabolic diseases not only helps to prevent patients from having a lifetime of suffering, it also saves lives.

Metabolic diseases have a variety of life-threatening consequences, such as heart disease and type 2 diabetes. The symptoms of some of these diseases are well-known and do not need intense specialised knowledge to identify. There are also the rare, inherited metabolic diseases that are much more difficult to identify. This is where the Centre for Human Metabolomics (CHM) of the North-West University (NWU) comes in.

The CHM is a research and commercial entity in the Faculty of Natural and Agricultural Sciences whose main focus is diagnostic testing for inherited metabolic diseases and research associated with these diseases. The CHM is also dedicated to providing the healthcare sector with innovative, cutting-edge analytical services.

Prof Chris Vorster, director of the CHM, explains: “One of the characteristics of metabolic diseases is that, over time, the clinical condition of a patient will deteriorate. This can happen very, very quickly, or the disease can have a slow and insidious onset. A typical scenario is a baby or a child who was well and then just suddenly started to deteriorate. Often there is neurological deterioration, so the level of consciousness decreases and they might develop convulsions or epilepsy and a number of other complications. Clinicians often cannot find a cause for this relentless deterioration. You can imagine that this can be a very frightening scenario.”

The rarity of these diseases means that they do not immediately spring to mind as a cause of the deterioration.

“However, we have done a lot of education in South Africa, and paediatricians in particular will consider an inherited metabolic disease during the diagnostic process and will send the appropriate samples to us.”

Prof Vorster says further that the types of inherited metabolic disease South Africans should be worried about does not differ from that in the rest of the world, as inherited metabolic diseases are entrenched in all populations. However, the frequency of the various diseases differs.

“In many parts of the world, phenylketonuria is a fairly common inherited metabolic disease. When I say common, I mean one in 10 000 to one in 20 000 births, whereas a rare metabolic disease will occur in one in a million births. In South Africa, the diseases that jump to mind are glutaric aciduria type 1, galactosemia, propionic acidaemia, Hunter syndrome, isovaleric acidaemia and congenital hyperthyroidism. The latter is not really a metabolic disease, but I name it as it is typically included in newborn screenings,” he says.

It is also during newborn screenings where the CHM are making the most valuable contributions.

“The work is extremely important. Together with the Red Cross, we are the only two entities in South Africa that offer testing for inherited metabolic diseases. The Red Cross mainly services the public sector, whereas we service the public and private sector. Without such centres, many patients with inherited metabolic diseases will go unnoticed. It is now established that genetic diseases, which include inherited metabolic diseases, are probably the leading cause of neonatal and infant mortality, particularly in infants of less than a year old. These are essential services. Many patients would suffer severe disability or even death if these diagnoses are not made.” 

It is a crucial task and – together with the CHM’s growing number of initiatives such as hosting the continent’s first exclusive rare disease biobank – an ongoing commitment to bettering the lives of all South Africans.  

Prof Chris Vorster.