Science makes headway in Africa

2012-11-11 10:00
Yolandi Groenewald
Local brain power used to find African cures for Africa’s diseases, writes Yolandi Groenewald

Do your genes and factors such as where in the world you live make you more prone to some diseases?

If you lived in the West, you would probably know, thanks to volumes of research produced on how your DNA and your environment can increase the chances of developing heart or liver disease or even cancer.

But the same cannot be said for Africans.

The failure to understand African genetics and genomics has hindered efforts to understand African health problems – until now.

The first-ever pan-African research programme into disease and DNA was launched last month in Ethiopia, and scientists from the universities of the Western Cape, Cape Town, Witwatersrand, Pretoria, Limpopo, Rhodes and Stellenbosch are playing a starring role.

The Human Heredity and Health in Africa (H3Africa) project will unravel how Africans’ genes deal with illnesses such as tuberculosis, heart disease and sleeping sickness.

Key H3Africa researcher Dr Nicki Tiffin, from the University of the Western Cape, says most of these studies were conducted on white people in North America and Europe.

But African populations are far more genetically diverse, which affects how effective existing treatments are.
Top researchers believe a thorough understanding of this is critical to understanding how to treat Africans in Africa.

“Besides depending on African scientists, the initiative will also develop research skills and infrastructure in Africa, so the research can take place on the continent without the loss of samples, expertise and scientific advances to other parts of the world,” said Tiffin.

Scientists know that many diseases can’t be blamed on a single cause, but they develop as a result of the combination of a number of factors such as the genes of the sufferer, environmental factors such as nutrition, or infectious agents like HIV.

The scientists’ findings will pave the way for future treatments.

Here is a bit about what they are up to:

Wits Professor Michèle Ramsay:
Cardiometabolic disease
Research conducted over the last 10 years shows that cardiovascular disease (heart disease) was the leading cause of death in the world except in Africa, where HIV/Aids was the number-one killer.

But heart disease was not far behind. However, very little is known about this killer in Africa, with researchers only scratching the surface now.

Add to this other cardio-metabolic diseases such as high blood pressure and obesity, and it is not difficult to see that Africa is sitting on a ticking health time bomb.

Enter Professor Michèle Ramsay, from the University of the Witwatersrand and the National Health Laboratory Service, who is trying to decipher what exactly is happening in Africa regarding this.

She heads the research project, titled Genomic and Environmental Risk Factors for Cardiometabolic Disease in Africans, that will look at high blood pressure and obesity in Africans.

The World Health Organisation estimates more than 30 million people in Africa suffer from hypertension.

It is also predicted that by 2020, three-quarters of all deaths in Africa may be caused by high blood pressure.

Ramsay has conducted extensive research on obesity, hypertension, bone development, HIV-related kidney disease and eye disease glaucoma in South African populations.

On this study, she will partner with the University of Limpopo and the INDEPTH Research Network Centres in Ghana, Burkina Faso and Kenya.

UCT Professor Bongani Mayosi: Rheumatic heart disease

Professor Bongani Mayosi is teaching children that sore throats could damage their hearts.

The University of Cape Town medical professor has been passionate about preventing heart disease caused by rheumatic fever ever since recording many young children living with damaged hearts after contracting this preventable disease. He wants to know why.

Mayosi heads the research project titled The RHDGen Network: Genetics – Of Rheumatic Heart Disease and Molecular Epidemiology of Streptococcus Pyogenes Pharyngitis.

It’s asking critical questions about why so many young Africans are dying of heart failure.

A huge concern is that common causes of heart failure in Africa include rheumatic heart disease.

This is in stark contrast to developed countries where heart failure is a disease of the elderly.

This can be traced back to rheumatic fever, caused by the common Streptococcus bacterium, which many African children come into contact with.

Already, scientists have found there is a great degree of genetic influence in the development of rheumatic
fever, the disease which causes rheumatic heart disease.

Mayosi has been passionate about preventing rheumatic fever, which too often attacks young children.

If left untreated, the disease, which is often first identified by a sore throat, leaves children susceptible to recurring heart conditions.

They can go on to develop a lifelong syndrome known as rheumatic heart disease, which often requires repeated surgery to replace faulty valves.

Dr Nicki Tiffin: Lupus nephritis

Why do some people’s immune systems suddenly decide to attack them? And are some more prone to this than others?

This is the question Dr Nicki Tiffin and her team are trying to answer by studying Cape Town residents with Lupus Nephritis, or inflammation of the kidneys caused by an overactive immune system that attacks normal, healthy tissues.

In Europe, extensive studies have been done to determine who might be more prone to develop this condition.

But in sub-Saharan Africa, there are few published studies on biopsy-proven lupus nephritis, mainly because of a shortage of laboratory capacity for performing the biopsies in many centres.

Tiffin worked on a study to determine clinical and laboratory models that could best predict Lupus Nephritis in South Africans.

“We are gathering clinical information about these patients, and will use this data to design and implement genomic studies to further understand the genetic and environmental contributors to this disease,” she said.

“Unfortunately, we have not started the genetic analysis yet: we are collecting a registry of patients with lupus through Groote Schuur Hospital, and are actively applying for funding to conduct the genetic studies,” he said.

The team are now looking at routine clinical data and will look for specific genetic markers that could predict
who will contract lupus.