CIRCANNUAL PATTERN OF AUTISTIC BIRTHS - REANALYSIS IN 3 ETHNIC-GROUPS

Seasonal variations in births of autistic subjects have been reported for the United States, Canada, Sweden, Japan, and Israel. Here, data f rom England, Japan, and Israel are reanalyzed using spectral analysis for the cosine function. A sample of 583 autistic births occurring ove r 40 years (1947-1989) is meta-analyzed, focusing on rhythmicity. Majo r periodicities of 17.6, 18.6, and 21.8 years, on which minor periodic ities ranging from 2.2 to 4.1 years were superimposed, yielded the bes t-fitting cosine function to significantly explain variance of autisti c birth patterns. It is interesting that the function composed of a ma jor period with several minor periods is remarkably similar in each of the three ethnic groups. In all three countries the acrophases (calcu lated function) aggregate in the period 1963-1970. In light of this ap parent universality of rhythms in autistic births across continents, w e call for further investigations into the role of environmental facto rs, possibly viral pandemics, in the etiology of autism.