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# About Autism Spectrum Disorder
- URL: https://yuriscihub.ghost.io/about-autism-spectrum-disorder/
- Published: 2026-11-01T20:11:38.000Z
- Updated: 2026-11-01T20:11:38.000Z
- Author: Yuriria Vázquez 

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder, present in childhood, involving distinct human deficits or difficulties around social communication and repetitive behaviors. Not every autistic person shares the same difficulties. However, some of the overlapping difficulties involve:

a) Social emotional reciprocity, i.e. how you share your social world.

b) Repetitive behaviors of interest and routines, as well as repetitive motor behaviors.

c) Infrequent or inappropriate use of gestures.

d) Challenges in social interactions and relationships.

Other difficulties involve high sensitivity to sounds, light, touch, smell or taste, as well as a lack of sensory reactions to pain, temperature or sounds. Although all of these features are diagnostic, individuals under the ASD umbrella often represent a wide range of severity and frequently present co-occurring signs and symptoms that can include anxiety, depression, sleep disturbance, epilepsy, or savant skills, e.g. an obsessive preoccupation with, and memorization of, music, maps, historical facts, etc.

Until 2019, according to the statistics, approximately 2.7-3.6% of the American population has been found to have an autism diagnosis. Unfortunately, the estimate has been rising over time. Although ASD ranks at the top of the neuropsychiatric disorders with regard to its relative genetic contribution and variety of clinical manifestations, we still do not have clear *diagnostic biomarkers* for it. One of the first successful efforts at isolating true ASD risk genes involved the identification of mutations in the *NLGN3* and NLGN4genes. These genes belong to a phylogenetically conserved family of adhesion proteins located at the postsynapse. Impaired function of the *NLGN3* and *NLGN4* genes is associated with ASD in humans and with impaired social behavior in mice. Nowadays, there is enough evidence to support the association of about a dozen copy number variant (CNV)\* loci and more than 100 genes with ASD, and this list is growing.

The fact that ASD involves very different human features poses a challenge for the interpretation of results coming from evolutionarily distant experimental models, e.g. mice. For this reason, in addition to the progress in gene discovery, there have been huge efforts to encourage what is known as the “*convergent neuroscience research approach”*, which involves the intersection of molecular-level, cellular-level and circuit-level functions across multiple ASD risk genes. This approach has revealed, among other things, that:

1) Developing excitatory neurons in the human cortex differ substantially between ASD and control subjects. In ASD subjects, the excitatory neurons in the developing frontal and parietal cortices show high expression of ASD genes during early mid-gestation.

2) ASD genetic risk may cause disruptions in cortical neurogenesis by disrupting network connectivity within the cortical layers.

3) ASD risk genes are differentially enriched in distinct cell types of the human brain. For example, post-mortem ASD human cortex reveals an increased representation of excitatory neurons and microglia in comparison with control brains.

In the last few years, there has been a global phenomenon of increasing autism prevalence. It is not clear what is changing in developing brains to make autism more common. Early diagnosis contributes to improving the cognitive skills of the ASD population. Thus, there have been tremendous efforts to generate biomarkers that allow for a quick and accurate diagnosis. Some of these efforts involve deep learning algorithms trained to detect particularities at the level of behavior (e.g. eye movements and facial gestures), brain imaging and circuits, as well as genetic profiles. Other strategies involve novel gene therapies such as gene replacement, editing, and antisense oligonucleotide strategies.

Early diagnosis, in combination with cognitive and behavioral therapies, is fundamental for improving the cognitive skills and quality of life of the ASD population. More work needs to be done in order to guarantee access to early diagnosis regardless of race, gender or social status. It is fundamental to reflect on how the ASD population perceives the world, what their needs are, and how we can adapt our environment and social constructions for them.

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\*Copy number variation (CNV) is a phenomenon in which sections of the genome are repeated, and the number of repeats in the genome varies between individuals.

**Sources & further reading:**

1) Willsey H.R. et al. (2022), Genomics, convergent neuroscience and progress in understanding autism spectrum disorder, *Nature Reviews Neuroscience*, 23, 323-341.

2) Autism by the Numbers: Explaining Its Apparent Rise (2021), *Spectrum*, Simons Foundation. [https://www.thetransmitter.org/wp-content/uploads/2025/01/Spectrum2021\_Autism-bythenumbersExplaining-apparentrise.pdf](https://www.thetransmitter.org/wp-content/uploads/2025/01/Spectrum2021%5FAutism-bythenumbersExplaining-apparentrise.pdf?ref=yuriscihub.ghost.io)

3) [https://autismwales.org/en/community-services/i-work-with-children-in-health-social-care/the-birthday-party/](https://autismwales.org/en/community-services/i-work-with-children-in-health-social-care/the-birthday-party/?ref=yuriscihub.ghost.io)

4) Embracing Autism, *A Little Help for Our Friends* Podcast

5) Spectrum, The Transmitter (Simons Foundation) [https://www.thetransmitter.org/spectrum/](https://www.thetransmitter.org/spectrum/?ref=yuriscihub.ghost.io)

6) Corthals K. et al. (2017) Neuroligins Nlg2 and Nlg4 affect social behavior in *Drosophila melanogaster*, *Frontiers in Psychiatry*, 8, 113.

7) Global Autism Prevalence Map, The Transmitter (Simons Foundation) [https://autismprevalence.thetransmitter.org](https://autismprevalence.thetransmitter.org/?ref=yuriscihub.ghost.io)

*Written by Yuriria Vázquez. Grammar and style were proofread with the help of Claude (Anthropic); all content, analysis and references are the author's work.*