This paper begins by reviewing the problem of determining whether there is a genetic factor in schizophrenia and homosexuality by considering the problem explaining the resulting apparently stationary polymorphisms. By analysing unpublished data on homosexuals it is concluded that the latter can not be explained by a genetic factor. The implications of the observed increases in parental age and parental loss in these diseases are then discussed, together with their implications for the genetic hypotheses.
References
1.
AbeK.MoranP. A. P. (1969). Parental age of homosexuals. Brit. J. Psychiat., 115: 313.
2.
BöökJ. A. (1953). A genetic and neuro-psychiatric investigation of a North Swedish population. Acta Genet. (Basel)., 4: 1, 133.
3.
CollmanR. D.StollerA. (1962). A survey of mongoloid births in Victoria, Australia, 1942–1957. Amer. J. Publ. Health., 52: 813.
4.
Essen-MöllerE. (1959). Mating and fertility patterns in families with schizophrenia. Eugen. Quart., 6: 142.
5.
GoodmanN. (1957). Relation between maternal age at parturition and incidence of mental disorder in the offspring. Brit. J. prev. soc. Med., 11: 203.
6.
KallmannF. J. (1952). Twin sibships and study of male homosexuality. Amer. J. Hum. Genetics., 4: 136.
7.
KallmannF. J. (1952). Comparative twin study of genetic aspects of male homosexuality. J. nerv. ment. Dis., 115: 283.
8.
KenyonF. E. (1968). Studies in female homosexuality. IV. Social and psychiatric aspects. Brit. J. Psychiat., 114: 1337.
9.
MoranP. A. P. (1968). Maternal age and parental loss. Brit. J. Psychiat., 114: 207.
10.
MoranP. A. P. (1971). Theoretical considerations in schizophrenia genetics. In: KaplanA. R. (Ed.) Genetic Factors in Schizophrenia. Thomas, Springfield.
11.
MoranP. A. P.AbeK. (1969). Parental loss in homosexuals. Brit. J. Psychiat., 115: 319.
12.
ParsonsP. A. (1964). Parental age and the offspring. Quart. Rev. Biol., 39: 258.
13.
ShieldsJ. (1968). Summary of the genetic evidence. J. psychiat. Res., 6. (Suppl. 1): 95.
14.
SlaterE. (1958). The monogenic theory of schizophrenia. Acta Genet. (Basel)., 8: 50.
