GENOMIC BANKING IN AFRICA
Some two hundred thousand years ago, Homo erectus and Homo neanderthalensis migrated throughout and from Africa to other regions. Scientists deduced this phenomenon with the help of genetic evidence. It was called the “Out of Africa” theory (OOA) [1]. Humans then evolved into Homo sapiens, and along the way interacted with various environments, climates and food and thus developed genetic changes [2]. But how significant are these changes? Well, that’s what genomic research is all about.
Genomic research is the search for variation in the DNA and humans share roughly 99.9 per cent of their DNA but it is the difference (mutation) in the remaining 0.1 per cent that is important. These mutations are known as SNPs (single-nucleotide polymorphisms) and most are benign, causing big ears, brown eyes or nothing at all but there are some (which scientists are more interested in) that cause damage such as – Alzheimer’s, high cholesterol, cystic fibrosis, thalassemia etc.
Recent genetic researches in medicine have unveiled new methods of diagnosis and treatment of patients. It has brought forth the age of precision medicine where each individual is given treatment and care tailored to his/her genetic makeup.
Medical genetics includes several subspecialties:
1. Prenatal, pediatric or adult genetics, which consists of diagnosing rare diseases of suspected genetic origin and counselling families.
2. Genetic oncology which focuses on genetic cancer risks and prevention in families.
3. Neurogenetics, which affects muscular and neurological diseases.
4. Cardiology that focuses on heart diseases
5. Molecular genetics and cytogenetics, which affect laboratory analyses, involves the development of diagnostic tests and the identification of new genetic mutations.
A relevant breakthrough in genetic medicine is the unearthing of knowledge that a single child acquired immunity to one of the deadliest diseases in the north African desert some thousands of years ago which was at the time significant because the land was forest laden and wet, a great habitat for mosquitoes. The immunity, a result of genetic mutation in hemoglobin (the molecule in red blood cells that carries oxygen), was passed on for generations. But that "power" came at a cost; sometimes if two of those descendants procreated, their children inherited two mutated genes and their red blood cells collapsed into crescents which in turn clogged their blood vessels. The result was a disease known as sickle cell anemia which brings severe pain and other complications like shortness of breath, strokes and vision problems.
The link between sickle cell anemia and malaria was established in the 1950s but the existence of the child was not known until 2018, when geneticist Charles Rotimi and his colleague Daniel Shriner at the US National Institutes of Health discovered it [4].
The mapping of the entire human genome – a 13-year effort list all of the roughly 3 billion ‘letters’ that make up a person’s DNA was completed in 2003 and yet till date it consists vastly of European genetic material with only 2% of African descent [3]. It was from this small portion Rotimi got his groundbreaking research. Now imagine if it consisted of more African genetic data, the complete understanding of the human genome in its entirety and the advancements in curing genetic related diseases is very possible.
African genomes are not only humanity’s oldest but also the most diverse, and that diversity holds within it an almost unfathomable potential from scientific breakthroughs to gene editing. Researchers, drug companies and start-ups around the world have recently woken up to the potential that Africa offers.
A consortium of roughly 500 African scientists are conducting paradigm shifting research on the genetic causes of Alzheimer’s, cancer, kidney diseases and other genetic related afflictions under the H3Africa (Human Heredity and Health in Africa) program funded by the NIH and the UK's Wellcome Trust in 2012 [4].
Botswana changed its first-line HIV treatment policies from Efavirenz-based therapies to Dolutegravir after studies shown that approximately 13.5 per cent of the population had two copies of the gene variant responsible for slow metabolism of Efavirenz [5]. In fact, pharmacogenomics studies have shown that the genetic allele CYP2B6*6, which causes slower rates of metabolism for several drugs, including Efavirenz is higher in African populations than Caucasians.
Dr. Olufunmilayo Olopade, one of America's leading cancer researchers who noticed that high rates of breast cancer were occurring at earlier ages in Nigerian women. In 2018, she co-authored the first ever study to use genomic analysis of African women. The results of this ongoing study could change the way we think about how breast cancer develops and how it should be screened for regardless of where you come from.
In 2019, Dr. Guida Landoure, an H3Africa-funded Malian researcher discovered in his lab a form of progressive myoclonic epilepsy caused by a genetic mutation that had previously been documented in two other patients, a German and an Italian [6]. The disorder can be treated with a cheap compound called folinic acid.
The gravely concerning issue is, who will ultimately own Africa’s genomic data. The commercial possibilities and gain become clear, private companies from foreign countries are beginning to take an interest. Scientists in Africa are struggling with the ethical implications of practicing science on a continent with a well-documented history of exploitation from abroad.
In 1996, Kano city was hit by the worst meningitis outbreak in Africa’s history, infecting 120,000 people [7]. Pfizer, a global pharmaceutical powerhouse saw an opportunity for phase 3 clinical trials, tricking people into thinking they were sending their kids to them to get treated. Pfizer paid $75m to settle the lawsuit in 2009.
During the 2014 Ebola pandemic, doctors and researchers from around the world took more than 269,000 blood samples from patients in Guinea, Sierra Leone and Liberia. None gave them consent for them to be used for research. But thousands of samples were sent to foreign labs and even beyond the lack of patient consent the researchers in the affected countries were left without access to the samples that in many cases they themselves collected.
Another dilemma presents itself; how do you obtain consent from people who might not even have the word ‘genes’ incorporated into their language yet, and even those who contributed how would you compensate. Variety of options include free access to diagnostic services, discounted access to the discounted drugs developed from their genetic material, donations to clinic or even the simply and ethically debated-cash.
Also, the funding from H3Africa will dry up in two years [6]. There is no sign of any government or institution ready to step in, the government doesn’t allocate enough budget to the health sector in general let alone a specified branch like genetics. The research results might also not even be in line with the governments priority for the health sector.
But the plethora of applications gene research can lead to will still pull investors in the future and is still too lucrative to turn down, be it Pharmacogenomics, disease diagnosis or Precision medicine.
Ibrahim Bello
Member NIMELSSA EDITORIAL TEAM 19/20
REFERENCES
1. Hublin JJ, Ben-Ncer A, Bailey SE, Freidline SE, Neubauer S, Skinner MM, et al. New fossils from Jebel Irhoud, Morroco and the pan-African origin of Homo sapiens. Nature. 2017; 546:289-92.
2. 1, OOO Genomes Project Consortium, Auton A, Brooks LD, Durbin RM, Garrison EP, Kang HM, et al. A global reference for human genetic variation. Nature. 2015; 526:68-74.
3. www.genome.gov/human-genome-project
4. Amy Maxmen et al. Nature 578,350-354(2020) Doi: 10.1038/d41586-020-00454-1
5. Mitropoulos K, et al. Success stories in genomic medicine from resource-limited countries. Human Genomics 2015; 7: 47.
6. www.h3africa.org
7. Wise J. “Pfizer accused of testing new drug without ethical approval” BMJ. 322 (7280): 194. Doi:10;1136/bmj.322.7280.194
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