Uniparental disomy (UPD) is a rare genetic abnormality. During a whole genome linkage study we identified a case of paternal uniparental isodisomy 3 serendipitously. This is the first ascertained human paternal UPD for chromosome 3 (UPD3pat).
View Article and Find Full Text PDFJ Clin Endocrinol Metab
March 2006
Context: Age at menarche (AAM) is an important anthropological variable that has major implications for a woman's health later in life. Genetic influence has been shown to contribute greatly to AAM, but the specific genetic determinants are largely unknown.
Objective: The objective of this study was to identify the quantitative trait loci (QTL) underlying the variations in AAM.
Parathyroid hormone/parathyroid hormone-related peptide receptor type 1 (PTHR1) plays an important role in calcium metabolism. It was previously shown to influence variation in bone mineral density (BMD). To investigate its importance in a typical U.
View Article and Find Full Text PDFObjective: Early onset of menopause results in the premature exposure to low estrogen levels and is associated with a number of postmenopausal health problems and higher risk of mortality. The aim of this study was to determine genetic and environmental factors associated with age at natural and surgical menopause.
Methods: Multiple regression analysis using a sample of Caucasians composed of 154 females with surgical and 248 with natural menopause.
Osteoporosis is characterized by a loss of bone strength, of which bone size (BS) is an important determinant. However, studies on the factors determining BS are relatively few. The present study evaluated the independent effects of height, age, weight, sex, and race on areal BS at the hip and spine, measured by dual-energy X-ray absorptiometry, while focusing on the differential contributions of height to BS across sex, race, and skeletal site.
View Article and Find Full Text PDFBackground: Ethnicity is shown to be one of important factors affecting bone mineral density (BMD). The present study was performed to compare the association of six markers for five candidate genes with BMD variation in two populations of different ethnicity, Caucasian and Chinese, and the contribution of genotype and ethnicity to this variation in the populations.
Methods: The studied restriction fragment length polymorphisms were BsaH I of the calcium-sensing receptor gene, SacI of the alpha2HS-glycoprotein (AHSG) gene, PvuII and XbaI of the oestrogen receptor alpha gene, ApaI of the vitamin D receptor (VDR) gene and BstBI of the parathyroid hormone gene.
Obesity is a condition of excess body fat that causes or exacerbates several major public health problems. Remarkable progress has been made in the molecular elucidation of monogenic forms of obesity both in rodents and in humans. The most common form of obesity, however, is considered to be a polygenic disorder arising from the interaction of multiple genetic and environmental factors.
View Article and Find Full Text PDFThis paper outlines information from recent publications that aid our understanding of bone quality in relation to osteoporosis. In practical terms, bone quality designates the properties of bone that contribute to strength but are not assessed by bone densitometry. While osteoporosis is still defined in terms of bone density, the limitations of this approach, long questioned, have become indisputable.
View Article and Find Full Text PDFObjective: To compare medication adherence with daily vs weekly bisphosphonate dosing for the treatment or prevention of osteoporosis in a broad US retail pharmacy database population.
Patients And Methods: From October 2002 through September 2003, the medication possession ratio (MPR = days of supply/365 days) was used to assess medication adherence. The MPR was calculated by use of daily and weekly bisphosphonate doses in a longitudinal cohort of patients who received prescriptions from 14,000 US retail pharmacies.
Unlabelled: Once-monthly (50/50, 100, and 150 mg) and daily (2.5 mg; 3-year vertebral fracture risk reduction: 52%) oral ibandronate regimens were compared in 1609 women with postmenopausal osteoporosis. At least equivalent efficacy and similar safety and tolerability were shown after 1 year.
View Article and Find Full Text PDFBone mineral density (BMD) is a major risk factor for osteoporosis. Circulating monocytes may serve as early progenitors of osteoclasts and produce a wide variety of factors important to bone metabolism. However, little is known about the roles of circulating monocytes in relation to the pathophysiology of osteoporosis.
View Article and Find Full Text PDFOral daily and weekly bisphosphonates represent the current mainstay of treatment for postmenopausal osteoporosis (PMO). However, the inconvenience of frequent dosing is known to negatively affect adherence to therapy in the long term. This has prompted the development of convenient oral bisphosphonate regimens that feature simple, less frequent dosing schedules.
View Article and Find Full Text PDFLeptin (LEP) and the uncoupling proteins 2 and 3 (UCP2/UCP3) are key molecules involved in the regulation of food intake and energy expenditure. However, their contribution to variation of obesity phenotypes in the general population remains controversial. The present study is to investigate whether chromosomal regions 7q and 11q, which contain LEP and UCP2/UCP3, respectively, can be excluded for linkage with obesity phenotypes.
View Article and Find Full Text PDFInterleukin 6 (IL-6) and tumor necrosis factor (TNF) are important cytokines for bone turnover. In this study, a promoter C-174G single-nucleotide polymorphism (SNP) within the IL-6 gene affecting the transcription rate of IL-6 and an exon 6 T676G SNP of the TNF receptor 2 (TNFR2) gene causing an M196R amino-acid change were examined for their relationship with bone mineral density (BMD). Four hundred and five multi-offspring Caucasian families, including 389 male children and 744 female children, were used.
View Article and Find Full Text PDFOsteoporosis is a common health problem among the elderly, especially postmenopausal women. It is characterized by fragile bones susceptible to low-trauma fractures. Osteoporosis is a complex disease determined by genetic and environmental factors, as well as the possible interactions among these factors.
View Article and Find Full Text PDFUncoupling protein 3 (UCP3) uncouples ATP production from mitochondrial respiration, thereby dissipating energy as heat and affecting the efficiency of energy metabolism. Genetic variations in the UCP3 gene have been conceived to affect body weight in the general population. In this study, using the quantitative transmission disequilibrium test (QTDT), we assessed linkage and association between the UCP3 gene and obesity phenotypes in a large sample of 1,873 subjects from 405 United States Caucasian nuclear families.
View Article and Find Full Text PDFObjectives: BONE (oral iBandronate Osteoporosis vertebral fracture trial in North America and Europe) determined whether less frequent dosing of ibandronate (dose-free interval > 2 months) provided similar antifracture efficacy to daily dosing. As osteoporosis medications must be effective across different populations, an additional objective of BONE was to investigate and report the effect of oral ibandronate in North American and European women, as described here.
Patients And Methods: BONE was a randomized, double-blind, placebo-controlled, fractureprevention study in 2946 postmenopausal women (age 55 years-80 years; > or = 5 years since menopause) with osteoporosis (low lumbar spine bone mineral density and one to four prevalent vertebral fractures [T4-L4]).
Curr Med Res Opin
February 2005
Objective: To compare the microarchitecture of iliac crest trabecular bone from women treated for two to three years with alendronate versus that of women treated with placebo.
Research Design And Methods: Three-dimensional micro-computed tomography (micro-CT; resolution 20 microm) and two-dimensional histomorphometry (resolution 5-7 microm) were used to examine trabecular bone from single transilial biopsies obtained at the completion of clinical trials.
Main Outcome Measures: Microarchitectural variables, including bone volume, trabecular number, trabecular thickness, and trabecular spacing in specimens from alendronate- and placebo-treated women were examined.
Expert Opin Pharmacother
March 2005
Risedronate sodium is an N-containing bisphosphonate that has been approved for the prevention and treatment of osteoporosis in postmenopausal women. An increase in the rate of bone remodelling is a regular feature of oestrogen withdrawal during the menopausal transition, but excessive remodelling leads to bone fragility. Risedronate and similar compounds reduce the rate of bone remodelling by suppressing the action of osteoclasts.
View Article and Find Full Text PDFUnlabelled: QUS measurements were made on 4139 female Army recruits at the beginning of basic training (BT). QUS predicted stress fracture in female recruits as well as it predicts hip fracture in elderly women. Recruits with low QUS values and a history of smoking and not exercising had an extremely high risk of stress fracture.
View Article and Find Full Text PDF