Children with autism have elevated levels of steroid hormones in the womb

autism
Quinn, an autistic boy, and the line of toys he made before falling asleep. Repeatedly stacking or lining up objects is a behavior commonly associated with autism. Credit: Wikipedia.

Scientists from the University of Cambridge and the Statens Serum Institute in Copenhagen, Denmark have discovered that children who later develop autism are exposed to elevated levels of steroid hormones (for example testosterone, progesterone and cortisol) in the womb. The finding may help explain why autism is more common in males than females, but should not be used to screen for the condition.

Funded by the Medical Research Council (MRC), the results are published today in the journal Molecular Psychiatry.

The team, led by Professor Simon Baron-Cohen and Dr Michael Lombardo in Cambridge and Professor Bent Nørgaard-Pedersen in Denmark, utilized approximately 19,500 samples stored in a Danish biobank from individuals born between 1993-1999. Amniotic fluid surrounds the baby in the womb during pregnancy and is collected when some women choose to have an amniocentesis around 15-16 weeks of pregnancy. This coincides with a critical period for early and sexual differentiation, and thus allows scientists access into this important window in . The researchers identified amniotic fluid samples from 128 males later diagnosed with an autism spectrum condition and matched these up with information from a central register of all psychiatric diagnoses in Denmark.

Within the amniotic fluid the researchers looked at 4 key 'sex steroid' hormones that are each synthesized, step-by-step from the preceding one, in the 'Δ4 sex steroid' pathway: progesterone, 17α-hydroxy-progesterone, androstenedione and testosterone. They also tested the steroid hormone cortisol that lies outside this pathway. The researchers found that levels of all steroid hormones were highly associated with each other and most importantly, that the autism group on average had higher levels of all steroid hormones, compared to a typically developing male comparison group.

Professor Baron-Cohen said: "This is one of the earliest non-genetic biomarkers that has been identified in children who go on to develop autism. We previously knew that elevated prenatal testosterone is associated with slower social and language development, better attention to detail, and more autistic traits. Now, for the first time, we have also shown that these steroid hormones are elevated in children clinically diagnosed with autism. Because some of these hormones are produced in much higher quantities in males than in females, this may help us explain why autism is more common in males."

He added: "These new results are particularly striking because they are found across all the subgroups on the autism spectrum, for the first time uniting those with Asperger Syndrome, classic autism, or Pervasive Developmental Disorder Not-Otherwise-Specified. We now want to test if the same finding is found in females with autism."

Dr Michael Lombardo said: "This result potentially has very important implications about the early biological mechanisms that alter brain development in autism and also pinpoints an important window in fetal development when such mechanisms exert their effects."

Steroid hormones are particularly important because they exert influence on the process of how instructions in the genetic code are translated into building proteins. The researchers believe that altering this process during periods when the building blocks for the brain are being laid down may be particularly important in explaining how genetic risk factors for autism get expressed.

Dr Lombardo adds: "Our discovery here meshes nicely with other recent findings that highlight the prenatal period around 15 weeks gestation as a key period when important genetic risk mechanisms for autism are working together to be expressed in the developing brain."

Professor Baron-Cohen said: "These results should not be taken as a reason to jump to blockers as a treatment as this could have unwanted side effects and may have little to no effect in changing the potentially permanent effects that fetal steroid hormones exert during the early foundational stages of brain development."

He cautioned further: "Nor should these results be taken as a promising prenatal screening test. There is considerable overlap between the groups and our findings showed differences found at an average group level, rather than at the level of accurately predicting diagnosis for individuals. The value of the new results lies in identifying key biological mechanisms during fetal development that could play important roles in atypical brain development in ."

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alfie_null
not rated yet Jun 03, 2014
From where might these elevated levels of hormones come? Were the subjects taking medication? Was it in the environment? Might be interesting to correlate autism incidence with use of hormones in, e.g. meat and dairy livestock, in different countries.
Benni
not rated yet Jun 03, 2014
Hormones of any kind in livestock feed have no place to go but into the food supply chain if it is consumed by humans. For animals to gain the so called benefits derived from hormones, those hormones must be absorbed into the animals body tissues to gain the desired attributes that hormones pass on, end result is foodstocks saturated with nothing less than poison.

Most of the meats found in supermarkets is no better than that served in a McDonalds, garbage unfit for human consumption.
ife
not rated yet Jun 03, 2014
Autism does start in the morula stage of development in the brain. I wonder if autism is a autoimmune disease. Women sometimes have sex with different men during their pregnancy can add unwanted antibodies into the womb while pregnant. Women sometimes have oral sex from men while they are pregnant can cause autoimmune. People can't understand the function of DNA synthesis is the ability to replicate.. Can our life style produce the fragile X syndrome for mental retardation gene found in autism. Women are usually mutation carriers and men are most often affected by the disorder. Duplication of part of chromosome 15 is implicated in one form of autism. Autism persons have severe speech impairment, and don't communicate. Wonder if multiple sex partners during the morula stage of pregnancy can cause mutable changes in the baby's development?
tadchem
not rated yet Jun 03, 2014
Elevated prenatal levels of steroid hormones would require some responsibility on the part of the mother. Such as concept is politically quite incorrect, no matter how physiologically valid it may be. The press, the liberals and the libertines will never accept it.
JVK
1 / 5 (1) Jun 03, 2014
Finally, they linked nutrient-dependent pheromone-controlled ecological variation to failed ecological adaptations manifested in behavioral phenotypes directly effected by diet-driven methylation and the pheromone-controlled physiology of reproduction.

Now, other researchers need only examine sex differences in the GnRH-directed LH response to pheromones. They can no longer attempt to explain sex differences in rates of ASDs as if they were more closely associated with mutations than with conserved molecular mechanisms of cell type differentiation in species from microbes to man.

Their explanations must include biological facts that link alternative splicings of pre-mRNA to downstream effects that also link the epigenetic landscape to the physical landscape of DNA in the organized genome of all species via the conserved molecular mechanisms we detailed in 1996. http://www.hawaii...ion.html
JVK
1 / 5 (1) Jun 04, 2014
Epigenetic effects on the GnRH pulse are the source of developmental disorders.

See: Study shows environmental influences may cause autism in some cases
http://medicalxpr...ses.html

Use of the same picture in both these news reports is worth 10,000 words of explanation.

As others have done here, simply ask: Where do the steroid hormones come from? When you realize how the epigenetic landscape becomes the physical landscape of DNA in the organized genomes of mammals, the conserved molecular mechanisms of ecological adaptations become clear. But they become even clearer when adaptations fail to correct for errors in steroidogenesis during development.