The Ratio of monozygotic to dizygotic affected twins and the frequencies of affected twins in unselected data
- 1 July 1958
- journal article
- research article
- Published by Cambridge University Press (CUP) in Acta geneticae medicae et gemellologiae
- Vol. 7 (3) , 313-320
- https://doi.org/10.1017/s1120962300019326
Abstract
SUMMARY With complete ascertainment, in populations with twin material unselected except for the presence of a specific trait (1) the ratio of ascertainable monozygotic to dizygotic twin pairs lies between ½ and 1 of the ratio in the general population and (2) the ratio of all ascertainable twin pairs to the total number of individuals lies between one and two times of that found in the general population. Formulae are derived which relate the frequencies of ascertainable twin pairs to the frequencies, from « suitable » parents, of the « affectable » genotype and to its penetrance. The calculated expectations are compared with some observed values.Keywords
This publication has 1 reference indexed in Scilit:
- Comments on the Analysis of Twin Samples—I. The Parent PopulationActa geneticae medicae et gemellologiae, 1955