by Josh Forman, Head of Science, Education & Outreach
A study published in Nature around January 2024, explored the evolutionary origins of Multiple Sclerosis (MS), offering a fascinating perspective on how genetic factors can influence disease susceptibility. While the study focused on MS, it also raises intriguing questions about other genetic diseases, particularly those prevalent within specific populations, namely for us, the Jewish population, which has a higher incidence of certain genetic disorders. I’m going to look to compare this ground-breaking work with Jewish genetic disorders (JGD) and explore some similarities and differences in their genetic underpinnings and potential implications for research and treatment.
MS is an autoimmune disease that affects the central nervous system, leading to symptoms like muscle weakness, fatigue, and vision problems.
Both JGDs and MS share a common characteristic: genetic predisposition. This means that individuals with certain genetic variants are more likely to develop these conditions. With MS, that predisposition is linked to Northern Europe (including the UK and Scandinavia) where individuals are twice as likely to develop MS than those from Southern Europe.
This appears to have been introduced to Europe approximately 5000 years ago by a group of cattle and sheep herders, known as the Yamnaya, moving into Northern Europe from what is now Western Russia, Ukraine and Kazakhstan, known as the Pontic Steppe. In fact, the genes involved in MS aren’t disease-causing mutations. The particular variations of the genes appear to have been an evolutionary advantage, fighting off animal pathogens from the herds.
The genes aren’t needed nowadays, with the advent of antibiotics and better hygiene. Instead, they seem to cause a predisposition to MS. This feels very similar to the well-known case of Sickle Cell Anaemia protecting against malaria when someone carries one version of the affected gene.
In the case of JGDs, it doesn’t seem that there was an evolutionary driver behind a genetic variation. The diseases are linked to particular genetic mutations that arose historically and have been passed down through generations within specific Jewish communities.
Understanding the genetic basis of both MS and JGDs has significant implications for research and treatment. By identifying the specific genes involved, scientists can develop targeted therapies that address the underlying genetic causes of these conditions. Additionally, genetic testing can help individuals at risk for these diseases to make informed decisions about family planning and preventive measures.
Could this be another case for Preconception Genetic Screening? MS is a life debilitating disease, with no cure. Modern medicine can significantly help to manage the symptoms and slow to progression of the disease, but it has a major impact on the quality of life for those suffering from its effects. Further studies on the same database of ancient DNA (generally extracted from bones or teeth found at ancient burial sites) are looking into other distinguishing genetic traits. One paper found evidence that genetic traits from the Yamnaya herders underlies why people of Northern European heritage are, on average, taller than those from Southern Europe.
Based on information reported here: https://www.bbc.co.uk/news/health-67917294
