Search results for "Dizygotic twins"
showing 4 items of 4 documents
Multiple sclerosis in twins from continental Italy and Sardinia: a nationwide study.
2005
Knowledge about the balance between heritable and nonheritable risk in multiple sclerosis (MS) is based on twin studies in high-prevalence areas. In a study that avoided ascertainment limitations and directly compared continental Italy (medium-prevalence) and Sardinia (high-prevalence), we ascertained 216 pairs from 34,549 patients. This gives a twinning rate of 0.62% among MS patients, significantly less than that of the general population. In continental Italy, probandwise concordance was 14.5% (95% confidence interval, 5.1-23.8) for monozygotic and 4.0% (95% confidence interval, 0.8-7.1) for dizygotic twins. Results in Sardinia resemble those in northern populations but in limited number…
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…
Twins. Similarities, differences and individuality
2015
This study aims to investigate the self-differentiating perceptions and the separation-individuation’s process in emerging adulthood twins. A group of 40 Italian pairs of twins (21 couples dizygotic-DZ and 19 monozygotic-MZ) aged 20-30 years, were evaluated using the test of graphic projection Family Life Space (DSSVF) and thought a specific questionnaire ad hoc constructed for this research. The research hypothesis focus on Zazzo’s test of parallel testimony and provide to give empirical evidence about the capacity of MZ Twins to use more internal resources of the couple than DZ Twins, causing the split slowdown on identification. The data show that there are no difference between not bise…
Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report
2015
Background: Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered during the clinical examination as a casual finding on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. Re…