Abstract
It is shown that the well known excess of females in anencephalic births is statistically significant when compared with (a) the general population and (b) their normal sibs.
There is also a statistically significant difference between the sex ratio of anencephalic births and that of spina bifida births which suggests that there is a definite difference in the genetic component of their aetiology.
These results are discussed with reference to the genetics of anencephaly and spina bifida and a genetic model of the inheritance of the genetic component of anencephaly is given. The significance of a possible cytoplasmic factor is also considered.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Böök J. A. & S. Rayner (1950). A clinical and genetical study of anencephaly.Amer. J. Hum. Genet. 2: 61.
Carter C. O., K. M. Laurence & P. A. David (1967). The genetics of the major central nervous system malformations based on the South Wales sociogenetic investigation.Develop. Med. Child. Neurol. 9: Suppl. 13. 30.
Coffey V. P. & W. J. E. Jessop (1955). Congenital abnormalities.Irish J. Med. Sci. 344: 30.
Collmann R. D. & A. Stoller (1962). Epidemiology of congenital anomalies of the central nervous system with special reference to patterns in the state of Victoria, Australia.J. Ment. Defic. Res. 6: 22.
Frezal J., J. Kelley, M. L. Guillemot & M. Lamy (1964). Anencephaly in France.Amer. J. Hum. Genet. 16: 336.
Macmahon B., T. F. Pugh & T. H. Ingalls (1953). Anencephalus, spina bifida, and hydrocephalus; incidence related to sex, race, season of birth and incidence in siblings.Brit. J. prev. soc. Med. 7: 211.
Nance W. E. (1969). Anencephaly and spina bifida: a possible example of cytoplasmic inheritance in man.Nature 224: 373.
Penrose L. S. (1946). Familial data on 144 cases of anencephaly, spina bifida and congenital hydrocephaly.Ann. Eugenics 13: 73.
Polman A. (1950). Anencephaly, spina bifida, and hydrocephaly.Genetica 25: 29.
Record R. G. & T. McKeown (1949). Congenital malformations of the central nervous system. 1. A survey of 930 cases.Brit. J. prev. soc. Med. 3: 183.
Registrar General (1968). Statistical Review of England and Wales for 1966. Part II. H.M.S.O. London.
Searle A. G. (1959). The incidence of anencephaly in a polytypic population.Ann. Hum. Genet. 23: 279.
Smithells R. W., E. R. Chinn & D. Franklin (1964). Anencephaly in Liverpool.Develop. Med. Child. Neurol. 61: 231.
Stevenson A. G. & H. A. Warnock (1959). Observations on the results of pregnancies of women living in Belfast. 1. Data relating to all pregnancies ending in 1957.Ann. Hum. Genet. 23: 382.
Timson J. (1969). The sex ratio in spina bifida.Genetica. 40: 427.
Williamson E. M. (1965). Incidence and family aggregation of major congenital malformations of the central nervous system.J. Med. Genet. 2: 161.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Timson, J. The sex ratio in anencephaly. Genetica 41, 457–465 (1970). https://doi.org/10.1007/BF00958926
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00958926