A lot of people here seem to assume that autism spectrum characteristics are genetic. Personally, I have my doubts. There may be some genetic factors, but the evidence for heritability is weak and what heritability there is could be social rather than genetic.
Of course, there haven't been a lot of environmental factors identified, either. That's why this article, showing a correlation between pregnancy spacing and autism, may be of interest:
http://pediatrics.aappublications.org/c ... 1.abstract
Quote:
An inverse association between IPI and odds of autism among 662 730 second-born children was observed. In particular, IPIs of <12, 12 to 23, and 24 to 35 months were associated with odds ratios (95% confidence intervals) for autism of 3.39 (3.00–3.82), 1.86 (1.65–2.10), and 1.26 (1.10–1.45) relative to IPIs of ≥36 months. The association was not mediated by preterm birth or low birth weight and persisted across categories of sociodemographic characteristics, with some attenuation in the oldest and youngest parents. Second-born children were at increased risk of autism relative to their firstborn siblings only in pairs with short IPIs.
02 Jul 2011, 12:46 pm
