Largest ever Arab genome study opens door to precision medicine

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Share on PinterestA large-scale analysis provides new insights into the genetic heritage of the Arab population. Jasmin Merdan / Getty Images

The Middle East is geographically at the intersection of human migration and culture. Even so, little historical research has been done into the genetic heritage of Arab populations. New research identifies complex differences in genomes that help map the origins and migrations of the Arab population.

Scientists from the Human Genetics Division of Sidra Medicine in Doha, Qatar, partnered with an international team of researchers to carry out the largest study of Arabic genomics to date.

The researchers analyzed the genomes of 6,218 people from the Qatar Biobank.

Based on this work, which was published in Nature Communications, the Qatari researchers concluded that the modern Arab population shares their genetic heritage with the oldest people in history. In addition, they have shown that the Arabs have great genetic diversity.

Study director Dr. Younes Mokrab – Assistant Professor at Weil Cornel Medicine in Qatar and Head of the Medical and Population Genomics Laboratory at Sidra Medicine – told Medical News Today:

“In general, due to the lack of sufficient genetic data on Arabs in the human ancestral landscape, it has long been assumed that Arabs were descendants of Europeans or very closely related.”

“Our study provides the first substantial genetic evidence that this is not the case. Genetically, Arab lineages are very different from Europeans. We discovered that the ancestors of modern Arabs are much older than the ancestors of modern South Asians or Europeans. Basically the Arab population is much older. “

“In addition, for a long time Arabs were seen as a more or less homogeneous population. However, even among the relatively small population of Qatar, we found several distinct genetic groups that reflect the broader Arab and Middle Eastern regions.

In their paper, the authors of the study find that the Arab population is divided into Qahtanite (Peninsula Arabs) and Adnanite Arabs (General Arabs and Western Eurasian Arabs).

As a result of their genomic work, the scientists came to the conclusion that the Arabs of the peninsula are the closest relatives of the ancient hunter-gatherers and the Neolithic farmers from the Levant – an area that encompasses the eastern Mediterranean including North Africa.

Using “genetic footprints” – the tracking of genetic mutations by individuals and populations – the researchers identified three significant periods of Arab migration: 70,000 years ago, 32,000–42,000 years ago, and then 12,000–20,000 years ago.

At this 20,000-year-old turning point, scientists identified an ancestral Arab population that dominated the Levant region: the Peninsula Arabs.

After comparing reservoirs of ancient DNA with people in the Qatar Genome Program (QGP), the researchers concluded that these groups are linked.

As MNT Dr. Asked how researchers identified these periods of Arab migration, Mokrab explained:

“Modern man is essentially descended from a small group of founding personalities. Our genetic makeup provides traces of how we deviated from each other. “

“In population genetics, we look at genetic mutations in large numbers of genomes to find out how populations are related and to trace when they started to differ from one another. In this study, we used state-of-the-art statistical methods to measure these relationships and to date the events of division that have taken place in the past and that have shaped the modern Arab population. “

“What is unique about our study is that we examined more than 6,000 Qatari genomes, for the first time on this scale. Not only did we find ancient events in this population, but we also compared the data with those of modern populations from different continents. “

“There we found evidence of a newer Arab genetic flow to Europe, Africa, South Asia and as far as South America. That fits in perfectly with what we know about the Islamic expansion from Arabia that began 14 centuries ago. “

In the Arabs they studied, the researchers found up to 20–50% genetic or blood related relationships between individuals.

This relationship is far higher among Arabs than among other ethnic groups. Such close family ties mean people are more likely to inherit genetic diseases.

Prior to this study, there was limited genomic data for Arab populations. This new data pool identifies genetic risks for Arab descendants and could largely improve medical care for all societies.

Dr. Mokrab observed:

“The high degree of consanguinity among the Arab population means that the likelihood of recessive genetic diseases is higher than in other parts of the world. Therefore, we are much more likely to discover rare forms of diseases which, through study, would lead us to a better understanding of common diseases affecting wider populations around the world. This is a real challenge and at the same time an enormous opportunity for discovery. “

Genomic studies are the first step in precision medicine, referring to the individual orientation of medical research and therapy.

The Qatari scientists and their international staff used this huge amount of data to create a genome panel for Arab people.

The researchers used their genome analysis to identify 12,432 haplotypes. Haplotypes are sequences of genes that appear consistently together and usually originate from one parent.

Geneticists around the world are quickly associating gene mutations with biological traits and diseases using genome-wide association studies. For Arabs, the first of its kind QGP “reference library” of haplotypes can help individuals identify and modify their risk of developing disease.

Regarding this genomic reference dataset, Dr. Mokrab versus MNT:

“We know that our genomes are made up of building blocks. So there are essentially markers within the genomes. If you have markers X, Y, or Z, it means your gene [always] looks like that. ‘ So you don’t really have to go there and sequence that part of the genome to know that! “

“The idea is that by using sequences of well-defined genomes for a given population, if you want to sequence the next few thousand people, you don’t necessarily have to sequence all of their genomes from scratch, you can just copy that.”

“This has a huge impact on how quickly we can scale things and what savings we can achieve as a result. Having such a panel for the Arab and Middle Eastern populations is a turning point for many countries in the region. “

Finally, Dr. Mokrab says his teams are adding Arabic genomic data – the QGP reference dataset of haplotypes – to level the genomic framework for all people of Arabic and Middle Eastern ancestry. With this data, nations in the region can study genomes and help their citizens with much less effort.

With the advancement of precision medicine, these Qatari researchers have given clinicians and patients a “head start” in diagnosing and combating disease at the gene level.