The genetic, environmental and phenotypic correlations of bone phenotypes at the spine and hip in Chinese.
BACKGROUND
Bone mineral density (BMD), bone mineral content (BMC), and bone size have been widely studied individually as important risk factors for osteoporotic fracture, but little is known about the correlation and the degree of sharing genetic and environmental factors between the pairs of the three phenotypes.


OBJECTIVE
The study investigated genetic correlation (rhoG), environmental correlation (rhoE) and phenotypic correlation (rhoP) between BMD, BMC and bone size.


METHODS
Bivariate variance decomposition analyses were performed in 904 subjects from 287 Chinese nuclear families.


RESULTS
Significant rhoE, rhoG and rhoP were detected between BMD, BMC and bone size, except for rhoE between BMD and bone size at the hip (rhoE = 0.121, p = 0.361). Common shared genetic factors explained 86.1% and 60% of BMD and BMC genetic variations at the spine and hip, respectively. However, the genetic and environmental correlations between BMD and bone size were limited. rhoE and rhoG at the spine were 0.392 and 0.381, and at the hip were 0.121 and -0.205, respectively. Only 14.5% and 4.2% of variations between BMD and bone size at the spine and hip may be due to the shared genetic factors.


CONCLUSIONS
The obtained results suggested that bone size may be used as another surrogate phenotype independently of BMD for eventual elucidation of the pathogenesis of osteoporosis because of the limited correlations between BMD and bone size.
Wang
Yan-Bo
YB
Laboratory of Molecular and Statistical Genetics and the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, PR China.
Lei
Shu-Feng
SF
Dvornyk
Volodymyr
V
Sun
Xiao
X
Jiang
De-Ke
DK
Li
Miao-Xin
MX
Deng
Hong-Wen
HW
D000328:Adult; D044466:Asian People / Q000235:genetics*; D015519:Bone Density / Q000502:physiology; D004777:Environment; D005260:Female; D006615:Hip / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010641:Phenotype; D013131:Spine / Q000033:anatomy & histology* / Q000502:physiology*