Heritability of clotting factors

Certain complex protein molecules in the blood, like the haemostatic factors, are thought to be present at higher levels in people who are likely to develop heart disease. Establishing to what extent the concentration of these factors is inherited is important for defining the role of genetics in coronary heart disease.

A step forward has been made by Marlies de Lange and colleagues, who analysed genetic and environmental effects on haemostatic factors in 1002 female twin pairs (Lancet 2001, 357:101-105). They found that genetic characteristics contributed to 41-75% of the variation in concentrations of haemostatic factors. Factor XIII activity showed higher (82%) and factor XIIa lower (38%) heritability. But age also had a significant effect on all factors, with all concentrations increasing with age.