TWIST1 gene SNPs may alter osteoporosis risk
MedWire News: Genetic analysis suggests that women with a mutation in the TWIST1 transcription factor gene may have a reduced risk for osteoporosis.
“Our observations suggest that the TWIST1 single nucleotide polymorphisms (SNPs) and haplotypes are candidates for genetic determinants of bone mineral density (BMD) of the hip in osteoblastogenesis,” report J-Y Lee (National Institute of Health, Seoul, South Korea) and co-workers.
Study findings indicate that the basic helix-loop-helix transcription factor TWIST1 inhibits cell differentiation and is involved in bone matrix formation and mineralization. However, little is known about the relationship between TWIST1 and BMD.
To investigate, the team examined for three TWIST1 SNPs in 729 postmenopausal women who had undergone BMD measurement. Over a quarter (27.3%) of the women had a BMD of less than –2.5[is there a value for this?] indicating osteoporosis.
Dominant analysis showed that women carrying one minor allele for the SNP +1871A>G in theTWIST1 gene had a significantly lower risk for osteoporosis than those who were homozygous for the common allele (odds ratio [OR]=0.42).
Dominant haplotype analysis for the –2072A>C, –372C>T +1871A>G, SNPs showed that patients carrying the Block1-ht1haplotype, with the A, C, and A alleles of the three SNPs had an increased risk for osteoporosis compared with women carrying the common minor homozygote genotype (OR=3.18). In contrast, women with the Block1-ht2 haplotype, with the C, C, and A alleles, had a reduced risk for the disease (OR=0.43).
In addition, women heterozygous for the +1871A>G SNP had significantly higher femoral neck BMD than those homozygous for the common allele, at 0.72 and 0.69 g/cm2, respectively.
Lee et al therefore conclude in the journal Osteoporosis International: “Further investigation of the mechanisms of TWIST1-mediated modulation of gene expression in bone cells should contribute to our understanding of osteogenic metabolism and provide a basis for the design of effective osteoporosis treatments.”
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By Lynda Williams