Genetic Determinants of the Population Variance in Bone Mineral Density

Abstract

Heritability refers to one possible explanation of variance in a trait such as areal bone mineral density (BMD). Heritability is the proportion of the total population variance (genetic plus environmental) in areal BMD attributable to genetic factors. The size of the total population variance depends on the factors chosen to describe the trait mean such as age, gender, height, and body composition. If total variance increases due to an increase in the environmental variance, without change in the genetic variance, heritability will decrease. Thus, heritability,a proportion,and genetic variance,an absolute,may give different impressions of the strength of genetic factors. Areal BMD is not a s..