Few Africans use potentially life-saving stem cell therapy.
The ratio is startling: only one in 500 000 black Africans take advantage of the therapy.
Stem cell therapy is said to be capable of treating about 70 diseases, including leukemia.
The Cryo-Save stem cell bank, launched a few weeks ago in Pretoria, has a mostly white clientele.
Its managing director, Louis Rehrl, said black Africans were estimated to make up less than 10% of the bank's clients.
Stem cell banking is a procedure that extracts stem cells from tissue taken from the umbilical cord or placenta when a baby is born.
Stem cells are the building blocks of the human body.
They are stored at the stem cell bank until they are needed to treat illnesses.
By October last year, 13 000 children in South Africa had had blood from their umbilical cord harvested and stored for stem cells.
Rehrl said few black South Africans banked their stem cells which meant they would struggle to find a matching sample - even on international registries.
In South Africa only private facilities offer the service. Cryo-Save is the biggest on the continent with branches in over 40 countries.
Rehrl said countries such as the US and Australia have public facilities but "the South African government will probably not consider a public facility for years to come".
He said this was probably because the government focused on other important issues, such as HIV/Aids and TB.
The stem cell-harvesting kit from the stem cell bank is given to the midwife before the birth of a baby. The cells are extracted from the baby's umbilical cord, loaded into the kit and taken to the bank.
Rehrl said cultural factors, such as people shunning some medical interventions for fear of seeming disrespectful, was a hurdle.
Though the body has its own stem cells, which help it to heal, he said umbilical stem cells were the most effective because they had not been exposed to chemicals, viruses or environmental teratogens.