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V Dvornyk

Publications and source records attributed to V Dvornyk.

6 recordsLinked to original sources
PubMed2004

A genome-wide linkage scan for bone mineral density in an extended sample: evidence for linkage on 11q23 and Xq27.

BACKGROUND: Osteoporosis is a major public health problem, mainly quantified by low bone mineral density (BMD). The majority of BMD variation is determined by genetic effects. A pilot whole genome linkage scan (WGS) was previously reported in 53 white pedigrees with 630 subjects. Several genomic regions were suggested to be linked to BMD variation. OBJECTIVE: To substantiate these previous findings and detect new genomic regions. METHODS: A WGS was conducted on an extended sample where the size was almost tripled (1816 subjects from 79 pedigrees). All the subjects were genotyped with 451 microsatellite markers spaced approximately 8.1 cM apart across the human genome. Two point and multipoint linkage analyses were carried out using the variance component method. RESULTS: The strongest linkage signal was obtained on Xq27 with two point LOD scores of 4.30 for wrist BMD, and 2.57 for hip BMD, respectively. Another important region was 11q23, which achieved a maximum LOD score of 3.13 for spine BMD in multipoint analyses, confirming the results on this region in two earlier independent studies. Suggestive linkage evidence was also found on 7p14 and 20p12. CONCLUSIONS: Together with the findings from other studies, the current study has further delineated the genetic basis of bone mass and highlights the importance of increasing sample size to confirm linkage findings and to identify new regions of linkage.

Bone Density↗
PubMed2003

Association of estrogen receptor alpha and vitamin D receptor gene polymorphisms with bone mineral density in Chinese males.

Osteoporosis is a common health problem not only in females but also in males, however, studies of osteoporosis in males are relatively rare compared to those in females. This is especially true in genetics studies. We evaluated the effects of PvuII and XbaI polymorphisms in the estrogen receptor alpha (ER-alpha) gene and ApaI polymorphism in the vitamin D receptor (VDR) gene on BMD variation in a random sample of 352 unrelated males from 401 Chinese nuclear families. BMD was measured at the lumbar spine (L1-L4) and hip (femoral neck, trochanter, intertrochanteric region). Raw BMD values were adjusted by age, age(2), height, and weight as covariates. We found no significant results for the 3 individual markers on BMD variation, however, ER-alpha haplotype analyses yielded some interesting results. Carriers of haplotype pX had a 4.98% lower BMD at the trochanter (P = 0.02) and 3.55% lower BMD at the lumbar spine (P = 0.09) than non-carriers. PX subjects had a 3.42% higher BMD at the trochanter and 3.26% higher BMD at the lumbar spine than others (P = 0.07 and P = 0.10, respectively). Such results were highly comparable with the significant or nearly significant interactions between ER-PvuII and ER-XbaI on BMD values at the trochanter (P = 0.03) and spine (P = 0.11). No significant results were observed for the interactions between ER-PvuII and VDR-ApaI, between ER-XbaI and VDR-ApaI, and between any of ER-alpha haplotypes and VDR-ApaI locus. Our results suggest that the ER-alpha haplotypes, not individual markers, may be associated with BMD variation at some skeletal sites in our Chinese male samples.

Absorptiometry, Photon↗
PubMed2003

Gene expression studies of osteoporosis: implications for microarray research.

Osteoporosis is one of the most common bone-related disorders in the elderly. It is a complex disease, and largely determined genetically. Traditional gene expression studies have shown that osteoporosis has complex regulating mechanisms which are controlled by multiple inherent factors, such as hormones, cytokines, various receptors, etc. The complex nature of osteoporosis, and the large number of genes involved in its onset and development, suggest the use of the state of the art microarray technique as a powerful tool to unravel mechanisms underlying etiology of osteoporosis.

Aged↗
PubMed2003

Differentiation of Caucasians and Chinese at bone mass candidate genes: implication for ethnic difference of bone mass.

Bone mineral density (BMD) is an important risk factor for osteoporosis and has strong genetic determination. While average BMD differs among major ethnic groups, several important candidate genes have been shown to underlie BMD variation within populations of the same ethnicity. To investigate whether important candidate genes may contribute to ethnic differences in BMD, we studied the degree of genetic differentiation among several important candidate genes between two major ethnic groups: Caucasians and Chinese. The genetic variability of these two populations (1131 randomly selected individuals) was studied at six restriction sites exhibiting polymorphisms of five important candidate genes for BMD: the BsaHI polymorphism of the calcium-sensing receptor (CASR) gene, the SacI polymorphism of the alpha2HS-glycoprotein (AHSG) gene, the PvuII and XbaI polymorphisms of the estrogen receptor alpha (ESR1) gene, the ApaI polymorphism of the vitamin D receptor (VDR) gene, and the BstBI polymorphism of the parathyroid hormone (PTH) gene. The two ethnic groups showed significant allelic and genotypic differentiation of all the polymorphisms studied. The mean FST was 0.103, which significantly differed from zero (P < 0.01). The Chinese population had lower mean heterozygosity (0.331) than the Caucasian one (0.444); the CASR-BsaHI and PTH-BstBI polymorphisms contributed most significantly to this difference. Analysis of the intra- and inter-population variability suggests that various types of natural selection may affect the observed patterns of variation at some loci. If some of the candidate genes we studied indeed underlie variation in BMD, their population differentiation revealed here between ethnic groups may contribute to understanding ethnic difference in BMD.

Asian People↗