A commingling analysis of obesity in the Tecumseh community health study

A commingling analysis of the distributions of obesity as quantified by Quetelet's index, triceps skinfold, suprailiac skinfold, umbilical skinfold, subscapular skinfold, a trunk‐extremity ratio of skinfold measurements and Quetelet‐adjusted trunk‐extremity ratio was performed in a population of 9,226 individuals living in Tecumseh, Michigan, during 1962–1965. For all but the (non‐Quetelet‐adjusted) trunk‐extremity ratio, two or three distributions were needed to fit the data adequately even after performing a power transformation to eliminate skewness. Although this evidence is compatible with a major gene effect, segregation analyses of these data using the unified, mixed model are necessary to resolve whether the commingling is due to a major gene.