The sex ratio in convulsive disorders with a note on single-sex sib-ships.

In many, and perhaps indeed in the majority of diseases, one sex tends to be affected more often than the other, and the convulsive disorders of children appear to provide an example of such a differential sex incidence. Lennox, Gibbs, and Gibbs (1940) in a series of more than 2,000 cases, found that 57% of their affected patients were male and 43% female. Lennox (1949), in a series of over 150 children with febrile convulsive disorders found a ratio of 62% males to 38% females, and she concluded that maleness was an aetiological factor to be given weight comparable with that of age, heredity, and degree of fever. This conclusion, if valid, is clearly of importance in the natural history of the syndrome and of general biological interest. In this paper we present an analysis based on a personal series of children with fits. The sex ratio we found was very like that of other workers, but on the general principle that any biological variation should be compared with that in a control group, we also studied the sex ratio in the unaffected siblings of our patients. The results obtained by this method seem to cast doubt on the validity of employing the sex ratio as a measure of the aetiological weight of sex in this or in other diseases. Our enquiry also showed a possible relationship between the hereditary factor in convulsive disorders and the sex ratio, both in the affected children and in their brothers and sisters.