CA repeat polymorphism of the TNFR2 gene is not associated with bone mineral density in two independent Caucasian populations.

Osteoporosis has a strong genetic component, but the genes involved are poorly defined. Genome-wide scans in multiple populations have identified chromosome 1p36 as one region linked to bone mineral density (BMD). The tumor necrosis factor receptor 2 (TNFR2) at 1p36 is a positional and functional candidate gene in osteoporosis. In this study, we conducted linkage and association tests between the CA repeat polymorphism of the TNFR2 gene and BMD in two large independent samples using the quantitative transmission disequilibrium test (QTDT) program. The first group of subjects was composed of 1836 individuals from 79 multigeneration pedigrees. The second group was a randomly ascertained set of 636 individuals from 157 nuclear families. We found no evidence of association or linkage for spine or hip BMD in the samples of the multigenerational pedigrees or nuclear families. Through testing for association and for linkage, our data do not support the TNFR2 gene as a QTL underlying hip or spine BMD variation in our Caucasian populations.