共查询到20条相似文献,搜索用时 15 毫秒
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F. Clarke Fraser 《American journal of human genetics》1955,7(3):321-322
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Paula Hertwig 《Molecular & general genetics : MGG》1919,20(3):269
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Wellesley D De Vigan C Baena N Cariati E Stoll C Boyd PA Clementi M;Euroscan Group 《Annales de génétique》2004,47(4):373-380
The objective of this study was to evaluate the contribution of ultrasound scanning to the prenatal detection of trisomy 21 in a large unselected European population. Data from 19 congenital malformation registers in 11 European countries were included. The prenatal ultrasound screening programs in the countries ranged from no routine screening to three ultrasound investigations per patient. Routine serum screening was offered in four of the 11 countries and routine screening on the basis of maternal age amniocentesis in all. The results show that overall 53% of cases of trisomy 21 were detected prenatally with a range from 3% in Lithuania to 88% in Paris. Ninety-eight percent of women whose babies were diagnosed before 24 weeks gestation chose to terminate the pregnancy. Centres/countries that offer serum screening do not have a significantly higher detection rate of trisomy 21 when compared to those that offer maternal age amniocentesis and anomaly scanning only. Fifty percent of trisomy 21 cases were born to women aged 35 years or more. In conclusions, second trimester ultrasound plays an important role in the prenatal diagnosis of trisomy 21. Of those cases prenatally diagnosed, 64% of cases in women <35 years and 36% of those in women >or=35 years were detected because of an ultrasound finding. Ultrasound soft markers accounted for 84% of the scan diagnoses. There is evidence of increasing maternal age across Europe with 50% of cases of trisomy 21 born to women aged 35 years or more. 相似文献
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Harold O. Goodman 《American journal of human genetics》1970,22(6):702-703
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Bonduriansky R 《Trends in ecology & evolution》2012,27(6):330-336
The refutation of 'soft' inheritance and establishment of Mendelian genetics as the exclusive model of heredity is widely portrayed as an iconic success story of scientific progress. Yet, we are witnessing a re-emergence of debate on the role of soft inheritance in heredity and evolution. I argue that this reversal reflects not only the weight of new evidence but also an important conceptual change. I show that the concept of soft inheritance rejected by 20th-century genetics differs fundamentally from the current concept of 'nongenetic inheritance'. Moreover, whereas it has long been assumed that heredity is mediated by a single, universal mechanism, a pluralistic model of heredity is now emerging, based on a recognition of multiple, parallel mechanisms of inheritance. 相似文献
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G. R. Fraser 《American journal of human genetics》1971,23(2):233-234
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Epigenetic heredity in evolution 总被引:1,自引:0,他引:1
We discuss the role of cell memory in heredity and evolution. We describe the properties of the epigenetic inheritance systems (EISs) that underlie cell memory and enable environmentally and developmentally induced cell phenotypes to be transmitted in cell lineages, and argue that transgenerational epigenetic inheritance is an important and neglected part of heredity. By looking at the part EISs have played in the evolution of multicellularity, ontogeny, chromosome organization, and the origin of some post-mating isolating mechanisms, we show how considering the role of epigenetic inheritance can sometimes shed light on major evolutionary processes. 相似文献
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Bateson W. 《Molecular & general genetics : MGG》1910,3(1):108-109
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