Coefficients of Relationship by Isonymy among the Parents of Scottish Twins: A Test of Familial Aggregation

Document Type

Article

Authors

Susan M. Holloway, Human Genetics Unit, University of Edinburgh, United Kingdom
J. A. Sofaer, Department of Oral Medicine and Oral Pathology, University of Edinburgh, United Kingdom

Abstract

The ability of the coefficient of relationship by isonymy R_i to detect familial aggregation of conditions suspected of being under a degree of genetic control was tested on groups of fathers and mothers of like-sex twins, fathers and mothers of unlike-sex twins, and fathers and mothers of singleton controls born from 1977 to 1981 in Scotland. No statistically significant difference of within-group or between-group R_i was found, either for all surnames or for rare surnames only. However, the overall pattern of results for rare surnames showed a measure of agreement with what is already known of the genetics of twinning. The relatively high within-group R_i for mothers of unlike-sex twins is consistent with a maternal genetic influence on dizygous twinning, whereas the relatively high between-group R_i for fathers with mothers of unlike-sex twins suggests that paternal as well as maternal genes may be involved. Values of R_i for the parents of like-sex twins raise the possibility of a paternal but not a maternal genetic contribution to monozygous twinning.

Recommended Citation

Holloway, Susan M. and Sofaer, J. A. (1990) "Coefficients of Relationship by Isonymy among the Parents of Scottish Twins: A Test of Familial Aggregation," Human Biology: Vol. 62: Iss. 3, Article 9.
Available at: https://digitalcommons.wayne.edu/humbiol/vol62/iss3/9