Autism Studies and Related Medical Conditions, January 2009 - TACA

autism may exhibit dysfunction of the HPA system, but it is not clear whether
altered neuroendrocrine regulation or altered responsiveness underlies the
differences between children with and without autism. In order to provide
preliminary data concerning HPA regulation and responsiveness, we compared
circadian rhythms and response to a non-social, environmental stressor in
children with and without autism. METHODS: Circadian rhythms of cortisol were
estimated in children with (N=12) and without (N=10) autism via analysis of
salivary samples collected in the morning, afternoon and evening on 2
consecutive days. HPA responsiveness was assessed by examining the time
course of changes in salivary cortisol in response to a mock MRI. RESULTS: Both
groups showed expected circadian variation with higher cortisol concentration in
morning than in the evening samples. The children with autism, but not typical
children, showed a more variable circadian rhythm as well as statistically
significant elevations in cortisol following exposure to a novel, nonsocial stimulus.
CONCLUSIONS: The results suggest that children with autism process and
respond idiosyncratically to novel and threatening events resulting in an
exaggerated cortisol response.
Danfors, T., A. L. von Knorring, et al. (2005). "Tetrahydrobiopterin in the treatment of
children with autistic disorder: a double-blind placebo-controlled crossover study." J Clin
Psychopharmacol 25(5): 485-9.
Twelve children, all boys, aged 4 to 7 years, with a diagnosis of autistic disorder
and low concentrations of spinal 6R-l-erythro-5,6,7,8-tetrahydrobiopterin
(tetrahydrobiopterin) were selected to participate in a double-blind, randomized,
placebo-controlled, crossover study. The children received a daily dose of 3 mg
tetrahydrobiopterin per kilogram during 6 months alternating with placebo.
Treatment-induced effects were assessed with the Childhood Autism Rating Scale
every third month. The results showed small nonsignificant changes in the total
scores of Childhood Autism Rating Scale after 3- and 6-month treatment. Post
hoc analysis looking at the 3 core symptoms of autism, that is, social interaction,
communication, and stereotyped behaviors, revealed a significant improvement
of the social interaction score after 6 months of active treatment. In addition, a
high positive correlation was found between response of the social interaction
score and IQ. The results indicate a possible effect of tetrahydrobiopterin
treatment.
Deth, R., C. Muratore, et al. (2008). "How environmental and genetic factors combine
to cause autism: A redox/methylation hypothesis." Neurotoxicology 29(1): 190-201.
Recently higher rates of autism diagnosis suggest involvement of environmental
factors in causing this developmental disorder, in concert with genetic risk
factors. Autistic children exhibit evidence of oxidative stress and impaired
methylation, which may reflect effects of toxic exposure on sulfur metabolism.
We review the metabolic relationship between oxidative stress and methylation,
with particular emphasis on adaptive responses that limit activity of cobalamin
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