Veins carry blood from the tissues and organs back to the heart. They do this uphill, so to speak, and have one-way valves to prevent the blood from flowing backwards. Sometimes these valves become weak and break and are not able to function properly. As a consequence there’s a build up of blood in the veins as it flows backwards and this leads to the characteristic bulges and distorted shape, recognised as varicose veins. There are many causes of varicose veins such as standing for long periods of time, heat, age, hormone changes in women and genetics. And though women form the largest group of sufferers, many men also complain of the condition.
Varicose Veins and Genes
That genes are somehow involved in causing varicose veins is attested to by the fact that so many people with the condition have had other family members who have had varicose veins in the past. So there’s something happening in the human genome to create the conditions for the valves inside veins to weaken and break down.
There hasn’t been a whole lot of work done on identifying candidate genes when compared to other fields of genetics but some genes have been implicated.
A 2005 study by researchers from Kyungpook National University School of Medicine in Korea identified 82 genes that were up-regulated (increased expression of genes) in the walls of varicose veins.
Researchers from St Thomas' Hospital and St Georges Hospital Medical in London carried out twin studies which implicated the FOXC2 region of chromosome 16 as playing a part in the development of varicose veins in general.
Over expression of genes encoding Matrix Gla Protein (MGP) could also be a contributory factor promoting varicose veins by helping to remodel the venous wall.
Knowledge of the genetic basis of varicose veins is still very much in its infancy. However, new research is continually implicating genes for further study as well as verifying and providing improved knowledge about genes previously indicated as playing a role. As well as figuring out how the condition starts and develops, an understanding of the genetic basis of the disease could offer ways of preventing and treating it, by controlling the action of the genes involved.
Gene Expression Profiles in Varicose Veins Using Complementary DNA Microarrays: Lee S et all: Dermatol Surg. 2005 Apr; 31 (4): 391-5
Linkage to the FOXC2 Region of Chromosome 16 for Varicose Veins in Otherwise Healthy, Unselected Sibling Pairs: M Y M Ng, T Andrew, T D Spector, S Jeffrey: Journal of Medical Genetics 2005; 42: 235-239
Identification of Differently Expressed Genes in Human Varicose Veins: Involvement of Matrix Gla Protein in Extracellular Matrix Remodelling: Chrystelle Cario-Toumaniantz et al. J Vasc Res 2007; 444-459