Mentally handicapped children, mostly in institutions, were screened in 5 countries in Africa in order to explore the usefulness of Western criteria for the recognition of childhood autism in developing countries. Approximately 1,300 children were seen, of whom 30 had some autistic-like behavior. Nine were autistic according to Western criteria. Autistic behavior was found in speaking and nonspeaking children of all grades; in sex ratio, occurrence of epilepsy, and social background the African group was broadly comparable to Western groups. Behavioral comparison with a British sample suggests some prominent features of the syndrome are very uncommon in Africa. Implications for recognition and classification are discussed. (Lotter, V. (1978). Childhood autism in Africa. Journal of Child Psychology and Psychiatry, 19(3), 231-44.)

The above is an old study, but it begs questions regarding increases in autism across the world. Which portions of the world are seeing the kinds of increases we’re seeing in the United States? Some sections of West Africa have far higher percentages of left handed children. Do those regions of higher or lower percentages of autism? Because diagnosis protocols differ, are there different rates of autism in African cities vs. African rural areas?

In addition to the reports mentioned earlier of increased frequency of allergies among stutters, celiac disease among autistic children and autoimmune thyroid disorders in their parents, and migraine among childhood dyslexics, a high frequency of food allergies (Tryphonas and Trites 1979) and atopic disorders (Geschwind and Behan 1984) have been reported among hyperactive children (p. 94). (Geschwind, N. & Galaburda, A. M. (1987). Cerebral Lateralization. Cambridge: MIT Press.)

Geschwind and Galaburda’s Cerebral Lateralization is crammed with information that suggests an etiology for autism. It is the first place that I know of that associated autism with a mother’s testosterone levels. When the book discusses allergies and autism, I am reminded that perhaps a mother’s allergies influence her testosterone, or even estrogen levels, and that those changing levels increase chances for conditions featuring maturational delay. I’ve wondered if the recorded season of birth effects associated with autism are related to when a mother’s allergies correlate with certain points in pregnancy when maturation rates are established.

As this post from yesterday’s Autisable notes, Vitamin D has been becoming more accepted as a possible explanation for some forms of autism. I’ve been proposing that light’s effect on the pineal gland has been regulating testosterone levels in directions that can cause autism, predicting in 1998 (sexualselection.org) that equatorial populations moving to northern climes would evidence higher percentages of autism.

Both my pineal theory, based on fluctuating testosterone levels, and the Vitamin D theory suggest that there would be clear season of birth effects with autistic children being conceived in certain times of the year. I’ve not seen studies that support that prediction.