The largest scale genomic study in Africa has identified a new gene that is linked to the onset of diabetes in African populations. Interestingly, the gene has not been found to be linked to diabetes in European populations.  

In type 2 diabetes the body is able to produce insulin but the body’s cells do not respond to it. This can lead to dangerously high blood sugar levels. As type 2 diabetes often develops in people as they age, understanding the genetic basis of the disease could lead to prevention treatments.

The genetic profiles of 5,231 people across Nigeria, Ghana and Kenya were investigated to identify the genetic variants shared by individuals with type 2 diabetes. Many genetic variants had already been identified from large scale studies of European populations, but the newly discovered gene ZRANB3 seemed to vary in diabetes patients of African origin.

Researchers attempted to understand how ZRANB3 was involved in diabetes by studying the pancreas in zebrafish. Using CRISPR the ZRANB3 gene was removed from the pancreas cells. When the gene was inactive the insulin producing β-cells of the pancreas underwent programmed cell death, known as apoptosis. When the ZRANB3 gene was knocked out in mice cells, they produced substantially less insulin.

This study demonstrates the value of large-scale genetic studies on different populations. Many population studies are done exclusively on European populations, even though key insights can be missed if people with different genetic backgrounds are excluded.

More studies are needed to identify if ZRANB3 is indictive of diabetes in other populations. Further studies are required to determine how ZRANB3 can cause diabetes in humans.