Sickle Cell Anemia Red cells in Blood Stream

By Onche Odeh

A team of researchers from Nigeria and the United States have recommended the use of gene editing technology in the treatment of common ailments and resolution of the food crisis in countries across Sub-Saharan Africa. They are optimistic that the new technology, if properly deployed can crash the cost of associated healthcare and feeding as currently borne by individuals in the region.

Specifically, they are proposing the adoption of  Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), an innovative gene-editing technology by the control programmes of  vector-borne diseases, like malaria and the fall army worm that have exacerbated public health and food security in the African region.

They are also hopeful that CRISPR could help in easing the management of Sickle Cell Anaemia and associated conditions.

In most African countries, the cost of healthcare is borne by individuals out of pocket. This, in addition to the unavailability of quality healthcare services due to gaps in technological applications and facilities, has caused many needless deaths among children and other population cohorts in the region.

A 2017 Nigerian study published by the National Centre for Biotechnology Information (NCBI) put the  economic cost of treating uncomplicated malaria in Nigeria at between 2,000 naira (US$9.14) and 7,600 naira  (US$37.99) per episode.

A similar study done in Nigeria for Sickle Cell puts the cost of outpatient visits at 1,000 naira (US$4) and about 10,000 naira (US$39). For cases requiring admissions, the study noted that patients were required to pay between 5,000 and 185,000 (US$30 and US$1,121).

The team from University of California, Irvine, California, United State and the Federal University Oye-Ekiti, in Nigeria noted in the perspective article published in the March 2019 edition of Trends in Biotechnology that with CRISPR this cost could be cut by a huge margin.

The lead author of the article, Christian Ogaugwu of the Department of Microbiology and Molecular Genetics, University of California, Irvine, USA, wrote that CRISPR highlights a timely fix that can benefit public health, medicine, and agriculture in SSA.

In an email response, Ogaugwu stated that the published work, which was at the time a perspective article’ written with inputs from colleagues in his home country, Nigeria highlights how CRISPR can be beneficial in solving malaria and other problems in Sub-Saharan Africa.

“I am working as part of a team based at the University of California Irvine and our current goal is to use CRISPR technology for malaria control,” Ogaugwu said while the work was in view.

He stated that some of the major outcomes from their works show how through CRISPR, Sub-Saharan Africa can suppress the spread of pests and by implication, the diseases that they carry. He said that the technology also holds huge benefit promises with Sickle Cell.

Explaining how CRISPR works, Ogaugwu stated that the technology which is based on CRISPR associated (Cas) proteins from bacterial immune systems was first developed using Cas9 endonuclease from Streptococcus pyogenes (spCas9) and has been ‘repurposed’ for gene editing utilizing a small guide-RNA (gRNA) with a changeable region of 20 nucleotide homology to a DNA target site to direct spCas9 to cleave the target DNA.

For malaria, they wrote that CRISPR/Cas9-based Gene Drives (GDs) have been developed for the mosquitoes, Anopheles stephensi and Anopheles gambiae.

According to the World malaria report by WHO, over 219 million cases of malaria were recorded in the last two years, 92% of which were in Africa. With over 400 different species of Anopheles mosquito; around 30 of which are malaria vectors of major importance, these researchers are hopeful that their works can add impetus to SSA’s malaria control efforts.

With Sickle-Cell Anaemia, a common disease in SSA caused by recessive mutant alleles of the oxygen carrier, hemoglobin S (HbS) inherited from parents by offspring, the authors say a correction of this mutation using CRISPR could abolish the disease in sufferers.

SCD is the commonest life-threatening genetic disorder among people of African heritage. The majority of people with SCD suffer from the most severe form of the disease—the homozygous HbSS genotype—which is also known as Sickle Cell Anemia (SCA).

A recent study by Professor Obiageli E. Nnodu, Professor of Haematology and Blood Transfusion at the University of Abuja Teaching Hospital Gwagwalada, Abuja, Nigeria and colleagues from Imperial College London, UK, Maternal, Newborn and Child Health, Institute for Disease Modeling, Bellevue, United States and Kenya Medical Research Institute (KEMRI)’ welcome Trust programmme, estimated that 300,000–400,000 babies with Sickle Cell Anaemia are born every year, about three quarters of them across a geographical band in Africa stretching from Senegal to Madagascar. This according to them is reflective of the continent’s malaria endemicity.

According to findings from the study published in the April, 2020 edition of the biomedical journal, BMC Medicine, “Over one percent of all newborns in the region have Sickle Cell Anaemia.”

Nigeria alone, the study noted, is home to 25–35% of global Sickle Cell births.

“In a recent review of cross-sectional population surveys and cohort studies of SCD in Africa, it was estimated that between 50 and 90% of SCA children died before age 5 years,” the study noted in the article, underscoring the need for countries to rejig in efforts towards the individual and collective case managements by deploying latest approaches.

According to the World Health Organisation (WHO), the African Region carries a disproportionately high share of the global malaria burden. In 2018 alone, the total funding for malaria control and elimination reached an estimated US$ 2.7 billion in the same year.

On food security, it has been estimated that the fall armyworm poses threats of $3-6 billion in annual damage to maize and other crops on the African continent.

Prof Dele Fapohunda, Chairman Board of Trustees, Mycotoxicology Society of Nigeria who is also Dean, School of Science and Technology at Babcock University, Ilishanremo, Ogun State, Nigeria said that CRISPR may just be the right “ingredient, in a sustainable intervention soup for the guarantee of health and food security in SSA.”

He said its adoption and application might provide the needed succour for the region’s aflatoxin problem. However, he said fears of unpredictable risk assessment and safety with prolonged use of CRISPR abound.

“The application must be proven to have advantages that far outweigh shortcomings,” he said in an interview, adding that, “An aggressive national awareness campaign, coupled with the appropriate actions from government regulatory agencies like National Biosafety Agency in Nigeria, is the driving force that will make Nigerians be part of the new field being covered by the new strategy.”

The team has said it is not oblivious of doubts, hence have recommended adequate awareness to educate local communities.

To also scale CRISPR implementation hurdles like international/national regulations and ethical guidelines, the team has urged absolute care, especially if the first CRISPR application in will SSA succeeds.

For a start, they are recommending a testing for success in Gene Drives (GD) mosquitoes in curbing malaria on small islands. They say this could likely be the prelude to the eradication of malaria on the continent and probably open door for implementation of other potential CRISPR applications.

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