The changing face of healthcare

Monday August 20 2018
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Recent advancements in the study of genes have improved our knowledge and allowed healthcare professionals to better understand its role in health and disease.

That’s why rare and common genetic disorders can now be identified more easily and treated promptly.

The success of this has been partly facilitated by a $1billion initiative, known as the human genome project that we have discussed in the previous articles in this column.

Researchers are now able to pin point the genetic difference in various populations and tell how differently these populations are affected with the same disease or respond to the same treatment because of their genetic differences.

How patients differ by region

Patients from a specific geographical region can differ on how they react to a drug when compared to patients from other regions.

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For instance, malaria is often treated by prescribing anti-malarial drugs such as amodiaquine and chloroquine. To work effectively, these medicines need to be broken down in the body, and this is done by an enzyme called CYP2C8.

However, if the individual has a defective variant of the same enzyme, so if a person has CYP2C8*2 instead of CYP2C8 then this results in poor breakdown of the medication in the body.

This can cause adverse side effects and has been associated to higher rate of malaria parasites that are resistant to chloroquine

In a study to see the prevalence of this defective enzyme, it was concluded that the defective enzyme was widespread in Africa and was significantly prevalent in Senegal when compared to populations in Uganda and Madagascar. This was published in the Malaria Journal.

Similarly, in the year 2015, Zimbabwe adapted a new single pill combination (efavirenz) to treat HIV. Thus replacing the standard three drug cocktail, following recommendations by the World Health Organisation(WHO).

This was meant to reduce costs and make it easier for people to administer the drug. Soon after thousands of Zimbabweans were put on the drug, many withdrew complaining of hallucinations, suicidal tendencies and depression.

In a research by Collen Masimirembwa, a geneticist in Harare, he found that many Zimbabweans carried a genetic variant, which slowed the ability to breakdown the efavirenz pill leading to accumulation of the drug in the body and adverse effects.

Using findings obtained by studying the drug response, the drug dosage was then reduced by 35 per cent.

Following such studies, it is important to establish genetic profiles of how drugs are used up by the bodies of various individuals as well as populations to improve treatment outcomes and drug use.

The world of precision medicine

Personalised medicine or precision medicine is a medical procedure that groups patients based on their genetic make-up.

Using their personal genetic data, medical professionals are in a better position to make well informed medical decisions such as predicting the risk of the occurrence of a disease, getting an accurate diagnosis or the specific management of a disease, all this suited to that one individual.

For example, the presence of certain gene errors in the DNA will predict a person’s risk of developing heart disease, type 2 diabetes, Alzheimer’s disease and cancer.

This patient can be advised that his/her genetic make-up is such that he or she is at high risk of the said diseases, which then gives the patient a chance to change lifestyle to actually prevent the disease onset.

Drawing from the above examples of how patients differ; in this world of precision medicine – researchers are able to develop therapies to actually target a certain population to suit their individual genetic make-up!

Africa’s genetic info underpresented

As much as the human genome project has been influential in studying diseases, drug interactions and drug production, the genetic details of African populations are severely underrepresented in the Human Genome Database, accounting for just 3 per cent of the total data.

This means certain drugs are more useful for treatment of diseases in populations outside of Africa (Europe and North America) and the African genome still remains to be inadequately explored for personalised medicine to be effective

Genomic medicine is becoming a cornerstone of medicine, if we do not act now, the growing differences in the knowledge relating to African genome and the rest of the world will continue to widen.

We can avoid this while the precision medicine initiative is still at its early years.