Search results for " twins"
showing 10 items of 73 documents
Genetic and environmental factors in health-related behaviors: Studies on Finnish twins and twin families
2003
Family, twin and adoption studies have provided evidence for familial and genetic influences on individual differences in disease risk and in human behavior. Attempts to identify individual genes accounting for these differences have not been outstandingly successful to date, and at best, known genes account for only a fraction of the familiality of most traits or diseases. More detailed knowledge of the dynamics of gene action and of specific environmental conditions are needed. Twin and twin-family studies with multiple measurements of risk factors and morbidity over time can permit a much more detailed assessment of the developmental dynamics of disease risk and the unfolding of behavior…
Genetic and environmental influences on longitudinal changes in leisure-time physical activity from adolescence to young adulthood.
2013
The aim of this study was to estimate genetic and environmental influences on the longitudinal evolution of leisure-time physical activity habits from adolescence to young adulthood. Data were gathered at four time points, at mean ages 16.2, 17.1, 18.6, and 24.5 years. At baseline, the sample comprised 5,216 monozygotic and dizygotic twins, born 1975–1979, and, at the last follow-up point, of 4,531 monozygotic and dizygotic twins. Physical activity volume was assessed as frequency of leisure-time physical activity and participants were categorized into three groups: inactive, moderately active, and active. Genetic and environmental influences were estimated using a multivariate, longitudina…
Genome-Wide Association Studies of the PR Interval in African Americans.
2011
The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n = 6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was p…
Depressive symptoms and career-related goal appraisals: genetic and environmental correlations and interactions.
2014
Abstract: In order to further understand why depressive symptoms are associated with negative goal appraisals, the present study examined the genetic and environmental correlations and interactions between depressive symptoms and career-related goal appraisals. A total of 1,240 Finnish twins aged 21–26 years completed a questionnaire containing items on the appraisal of their career goals along five dimensions: importance, progress, effort, strain, and self-efficacy. In the same questionnaire, the 10-item General Behavior Inven- tory assessed depressive symptoms. Structural equation modeling was used to evaluate the genetic and environmental correlations and gene–environment interactions be…
Ankylosing spondylitis in monozygotic twins: studies on immunological parameters
1999
OBJECTIVE—To examine immunological parameters that might explain disease discordance in monozygotic twin pairs with ankylosing spondylitis (AS). METHODS—11 monozygotic twin pairs (nine with AS, two with undifferentiated spondyloarthropathy) were investigated. The peripheral T cell receptor Vβ repertoire was investigated using FACS analysis and 14 different Vβ antibodies. In addition serum samples were tested for antibodies to Klebsiella pneumoniae, Streptococcus pyogenes, Candida albicans, Proteus mirabilis, and Escherichia coli. Peripheral blood lymphocyte reactivity against a number of bacteria was investigated by interferon γ ELISPOT assays. RESULTS—Twins suffering from AS showed cellula…
Thanatophoric dysplasia in monozygotic twins discordant for cloverleaf skull: Prenatal diagnosis, clinical and pathological findings
1992
We present male monozygotic twins with thanatophoric dysplasia (TD) type I concordant for long bone abnormalities and discordant for cloverleaf skull. The twins were the product of the second pregnancy of unrelated parents, with advanced paternal age. Prenatal diagnosis and postmortem examination showed severe rhizomelic shortness of limbs, bowing of the long bones with "telephone-receiver" femora in both twins, and cloverleaf skull and hydrocephalus in one of them. It is now accepted that most of cases of TD, such as in the present report, represent an autosomal dominant mutation with a high new mutations rate.
Lifetime exercise and disk degeneration: an MRI study of monozygotic twins.
1997
Participation in some competitive sports has been shown to increase disk degeneration; however, the long-term effects of recreational physical activities are unclear. We investigated the effects of endurance exercise and power sports on disk degeneration in monozygotic male twins with contrasting lifetime exercise histories. The effects of endurance exercise were studied in 22 discordant twin pairs (mean lifetime frequencies of 3.9 vs 1.1 times/wk), and the effects of power sports were investigated in 12 discordant pairs (2,300 vs 200 h of weightlifting). The age range of the twins was from 35 to 69 yr. No differences in MRI findings between co-twins discordant for endurance exercise were f…
Development of a Food-Based Diet Quality Score from a Short FFQ and Associations with Obesity Measures, Eating Styles and Nutrient Intakes in Finnish…
2019
We constructed a food-based diet quality score (DQS) and examined its association with obesity measures, eating styles and nutrient intakes. Participants were 3592 individuals (764 dizygotic [DZ] and 430 monozygotic [MZ] twin pairs) from the FinnTwin16 study. The DQS (0&ndash
Differences in Corneal Anatomy in a Pair of Monozygotic Twins Due to Continuous Contact Lens Wear
2003
Purpose To study the differences in the corneal anatomy in a pair of 31-year-old monozygotic female twins, one of whom has been a contact lens wearer for the past 15 years and the other is a nonwearer. Methods We analyzed the corneal thickness and the corneal endothelial cell density of the monozygotic twins and of two age-matched control groups, one made up of non-contact lens wearers (35 eyes of 35 patients; mean age, 29.32 +/- 2.83 years) and the other made up of soft contact lens wearers (30 eyes of 30 patients; mean age, 33.08 +/- 3.72 years; mean duration of contact lens use, 10.62 +/- 4.32 years). Five corneal thickness measurements were carried out with the Orbscan Topography System…