Despite the fact that up to 30% of the population suffer with varicose veins at some point in their lives, we still don’t know why.
Some speculate it’s environmental, that it comes from working a job with too much legwork, too much walking; others that it’s too much sitting. Famous doctor William Osler cites genetics- if your mum and dad had them, chances are you will too.
But it’s been difficult to prove a genetic link in varicose veins because of their commonality. With rare medical conditions it’s relatively easy to trace a family link back to the disease. Not so with varicose veins- until now.
Recent research in the Journal of Clinical Investigation looks at mice. Specifically, the venous valves in mouse embryos.
Valves are the crucial structure in veins- they are the reason blood is able to progress up the vein, against gravity, back to the heart. It is when these valves fail that we see varicose veins. We have known the importance of valves in vascular health for hundreds of years. But the way they develop has been unclear.
Using a high-tech electron microscopy, scientists have now been able to map out how vein valves actually form in the earliest stages of development.
The new evidence supports the idea of a genetic component in the development of varicose veins. The development of valves in the veins and lymphatic channels of mice embryos were linked with specific genes, to determine the role and structure of said valves.
This is itself a major technical achievement, but scientists were actually able to further identify which parts of the vein are destined to become valves by using specific markers on ‘programmer’ genes in the cells. They found they were able to track cells inside the veins, determining whether they become valves or ordinary cells in the wall of the vein.
Researchers found that by interfering with the genes identified as being important in valve development, they could stop valves forming in the mouse embryo. This manipulation also affected valve formation in the heart, too, suggesting vein and heart valve development are related.
What all this means for us is that we suddenly have a hugely improved understanding of how human tissue develops. Work of this kind could become the basis of drug development to influence, or even correct, vein malfunction that causes varicose veins to form. We’re another step closer to figuring out why varicose veins happen to some and not to others.
In the meantime, William Osler may have been right –it looks as though if you have varicose veins you probably can blame your parents.
written by Eddie Chaloner a consultant vascular surgeon operating at the specialist vein clinic Radiance Health.