Autism, also known as autism spectrum disorder (ASD) is a developmental disorder that affects the brain. The signs of this disorder according to the CDC can present in, “significant social, communication and behavioral challenges.” These challenges often begin to emerge around early adolescence, but can even be diagnosed as early as 18 months in some cases (CDC). The symptoms most relevant to today’s discussion are those that deal with social interaction with others. These symptoms include, “having trouble relating to others or not have an interest in other people at all, avoid eye contact and want to be alone, having trouble understanding other people’s feelings or talking about their own feelings, and lastly, be very interested in people but not know how to talk, play, or relate to them.” All these symptoms come from the CDC and include other forms of symptoms that do not relate to social interaction.
Dr. Maggie Guy of Loyola University Chicago Psychology department gave a presentation, on her work with brain responses in infants to faces vs objects. The findings of this research related ability to show that the P1 and N290 both regions in the fusiform gyrus are more responsive to faces than to objects. During her presentation she discussed her more recent advancement from this research and how she was applying this data and using it to study the brain activity for infants ages 4.5 to 12 months for those that have fragile X syndrome or have siblings that have ASD. The use of these two populations was to form a brain model to see if there was any significant difference between healthy brain models and the one produced by Dr. Guy. The findings showed a moderate difference that requires further study and a larger group of participants to allow for the brain models to be more precise and applicable for the populations of study. This research has the possibility of becoming a useful tool in the diagnosis of ASD along with other traditional methods. If the model from Dr. Guy’s lab is shown to be a consistent predictor of a patient's future diagnostics for autism this would give doctors another tool to help diagnose and apply interventions earlier.
One group that will dramatically benefit from this research is girls and women that don’t get a diagnosis of ASD until later in life. The difference in rates of autism among boys and girls is well documented, with a ratio of about 4 boys being diagnosed with autism to every one girl being diagnosed. Two theories have been presented about what could be the cause for this drastic difference in autism prevalence between boys and girls. The first theory is that girls are underdiagnosed or miss diagnosed and thus are not included in the statistics on autism in girls. The other theory is that due to genetic differences between boys and girls that boys are more predisposed to have autism than girls. The first theory was analyzed by Dean Michelle and colleagues through an examination of previous studies on social interactions of ASD children and non-ASD children. Their analysis took the data on social interaction and friend group formation and separated the responses and ratings by the children according to their gender and a previous diagnosis of ASD. The findings of the analysis showed that of the four groups of study (non-ASD boys, non-ASD girls, ASD boys, ASD girls), “boys with ASD were rejected more frequently than all other groups, suggesting that their social exclusion may be easier to detect than the exclusion of girls with ASD (Michelle 2015).” This finding offers insight into one major reason why girls are less likely to be diagnosed at the same age as boys if they even receive a diagnosis at all. Being able to identify the difference in ASD behavior between boys and girls is fundamental to ensuring that no person male or female goes with the beneficial support of a diagnosis and early intervention to help with navigating society with autism.
The second theory that offers a possible explanation for the difference in diagnosis rates for girls comes from the study of retinoic acid-related orphan receptor alpha (RORA) a regulator of development, metabolism, and immune function. This receptor shares the same gene modification pathway as sex hormones like testosterone (Hu 2015). In previous studies, a strong correlation between RORA and aromatase protein and gene expression helped to support a model that elevated levels of testosterone in the brain were found in some cases of ASD (Hu 2015). Within the study it was found that within cortex tissue samples the expression of RORA was nearly the same for both males and females, thus offering a possible hypothesis that RORA levels in the female brain could offer some protection or threshold protection from ASD given the lower prevalence of ASD in the female population. Further study is needed into possible gene knockout effects in animal models to determine if there is a percentage that when reached offers protection from ASD or an increased likelihood of being diagnosed with ASD (Hu 2015). In the study through the use of neuronal cell models, RORA showed the ability to bind to the promoter region of over 2,500 genes, 438 of those genes are found in autism gene databases (Hu 2015). Overexpression of these genes can result in, “neuronal differentiation, neuron projection morphogenesis, axonogenesis, and axon guidance,” all of these genes through over or under expression can result in neurological developmental disorders like ASD (Hu 2015).
Further study and research are needed to fully understand the molecular and social aspects of ASD and how it presents differently for males and females in the population. Both studies offer a different possible explanation for the drastic difference in the number of males diagnosed with autism to the number of females diagnosed with autism. The goal of future research should be to help diagnose those with ASD at an earlier age and help to apply earlier intervention that allows those with ASD to have better tools to navigate the world of those without ASD.
Works Cited
Conte S, Richards JE, Guy MW, Xie W, Roberts JE. Face-sensitive brain responses in the first year of life. Neuroimage. 2020 May 1;211:116602. doi: 10.1016/j.neuroimage.2020.116602. Epub 2020 Feb 8. PMID: 32044434; PMCID: PMC7085434.
Dean M, Kasari C, Shih W, Frankel F, Whitney R, Landa R, Lord C, Orlich F, King B, Harwood R. The peer relationships of girls with ASD at school: comparison to boys and girls with and without ASD. J Child Psychol Psychiatry. 2014 Nov;55(11):1218-25. doi: 10.1111/ jcpp.12242. Epub 2014 Jul 16. PMID: 25039696; PMCID: PMC4269475.
Hu, V.W., Sarachana, T., Sherrard, R.M. et al. Investigation of sex differences in the expression of RORA and its transcriptional targets in the brain as a potential contributor to the sex bias in autism. Molecular Autism 6, 7 (2015). https://doi.org/10.1186/2040-2392-6-7
“What Is Autism Spectrum Disorder?” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 25 Mar. 2020, https://www.cdc.gov/ncbddd/autism/acts.html.
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