Anthropometric and bone-related biochemical factors are associated with different haplotypes of ANKH locus.
BACKGROUND
The human homologue of the mouse progressive ankylosis (ANKH) gene is one of the key genetic factors involved in bone mineralization. Previous studies have shown that plasma levels of osteoprotegerin (OPG) and parathyroid hormone (PTH) are associated with the distal region of the ANKH gene, whereas skeletal size measurements are associated with the promoter region.


OBJECTIVE
The present study examines the possible phenotype-haplotype specificity of the associations in these two gene regions.


METHODS
The total sample consists of 1249 healthy individuals (mean age = 47.7, SD = 16.8) from 404 nuclear families. Fifteen interrelated anthropometric measurements were transformed into two principal components, reflecting body size and mass. Those, plus circulating levels of PTH and OPG, were subjected to association analysis, using transmission disequilibrium tests (TDTs) with ANKH gene. From 805 to 1150 individuals per SNP were genotyped.


RESULTS
In the proximal region (rs3006069-rs835154-rs835141), associations were found between the A-A-C haplotype and the first principal component reflecting body size (p < or = 0.048), whereas another haplotype, G-G-C, was associated with the first principal component, reflecting the body mass (p < or = 0.008). In the distal region of ANKH (rs39968-rs696294-rs875525), the A-A-C haplotype was found to be associated with OPG plasma levels (p < or = 0.001), whereas the G-A-C haplotype was associated with PTH circulating concentrations (p < or = 0.025).


CONCLUSIONS
Taken together, the results show discrimination between the corresponding regions and haplotypes, suggesting trait-specific gene variants that influenced bone-related phenotypic variation in the studied population.
Korostishevsky
Michael
M
Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel.
Vistoropsky
Yulia
Y
Malkin
Ida
I
Kobyliansky
Eugene
E
Livshits
Gregory
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000886:Anthropometry / Q000379:methods*; D001835:Body Weight; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D008875:Middle Aged; D053244:Osteoprotegerin / Q000235:genetics*; D010281:Parathyroid Hormone / Q000235:genetics*; D028061:Phosphate Transport Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D044465:White People / Q000235:genetics
C498770:ANKH protein, human; D053244:Osteoprotegerin; C470125:PTH protein, human; D010281:Parathyroid Hormone; D028061:Phosphate Transport Proteins