Autism Spectrum Disorder (ASD) Explained

Read Part Two: Genetics of Autism Spectrum Disorder

Collaboratively written and edited by: Joan Kornkven, Megan Lew, Rachel Baer, Mark Schmertmann, MSW, LSW, and Andy McCarty, MS, CGC

 

SUMMARY: ASD is complex, but a better understanding of how it presents has increased earlier diagnoses and has allowed more people with ASD to be recognized (12). The increase in prevalence means schools and clinics need to be better equipped to help those with ASD. Under the 1975 Individuals with Disabilities Education Act (IDEA), states must provide children with an education that meets their individual needs (13). Schools must legally provide any accommodations that a child needs, however, they do not need to provide the most optimal or best choice. It is important to advocate for individuals with ASD to get the best care possible as early as possible. At the same time, a better understanding and awareness of ASD would decrease its stigma and allow for ASD to be seen as a difference that requires non-traditional approaches within education, healthcare, and daily living rather than a disorder.

 
 

Clover Genetics can provide genetic counseling for those with diagnosed or suspected ASD as well as facilitate genetic testing reviewed by both a genetic counselor and a physician. We offer post-test counseling to discuss the results and provide answers to questions, resources, and support for each patient.

On This Page:

  • Definitions

  • Defining Autism Spectrum Disorder (ASD)

  • Differences in Expression

  • Citations

 

Important Definitions:

Autism Spectrum Disorder (ASD)

A developmental disorder of variable severity that is characterized by difficulties in social interaction and communication and by restricted or repetitive patterns of thought and behavior (14).

Neurotypical

People with typical neurological development or function; Those who do not display or experience characteristics of neurologically diverse patterns of thought or behavior like: Autism Spectrum Disorder (ASD), Attention Deficit Disorder / Attention Deficit Hyperactivity Disorder (ADD/ADHD), Obsessive Compulsive Disorder (OCD), or other neurological or neuropsychiatric differences are considered neurotypical (14).

Neurodivergent

People who display or experience characteristics of neurologically diverse patterns of thought or behavior like: Autism Spectrum Disorder (ASD), Attention Deficit Disorder / Attention Deficit Hyperactivity Disorder (ADD/ADHD), Obsessive Compulsive Disorder (OCD), or other neurological or neuropsychiatric differences are considered to be neurodivergent (14).

Assigned Male/Female At Birth (AMAB or AFAB)

The sex (male or female) assigned to a child at birth, which is most often based on the baby’s external anatomy (15). This is separate from the construct of gender and is strictly based on the doctor’s initial impression of the baby’s sex at birth.

Non-speaking

A descriptor for a person who either does not learn how to speak, is unable to speak, or is uncomfortable speaking for any reason including neurologic underdevelopment, traumatic brain injuries, or other physical conditions, like problems with the vocal cords (16).

Non-speaking Autism

A person with ASD who does not speak or only speaks with few words. Some people with ASD prefer to utilize alternate forms of communication because they find communicating through speech to be more difficult even if they are physically capable of speech. Some affected individuals write and verbally communicate in other ways such as typing or through special communication devices. Non-speaking individuals are generally still able to comprehend language (17).

Genome

The complete set of genes or genetic material present in a cell or organism (14). This includes the genetic material that codes for genes. Genes are responsible for making the proteins that help us to function. The genome includes non-coding genetic material that does not code for genes but rather regulates the activity level of the genes and plays other roles.

Exome

The part of the genome that includes DNA that codes for proteins, or genes. These coding genes are in groups called exons, which are the only thing included in the exome (18).

 

Defining Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is challenging to define because it has a wide range of expressions that are becoming increasingly identified and recognized as linked to ASD. The understanding that ASD presents differently for each person on the spectrum has also presented challenges in diagnosis. One definition of ASD is that it is a developmental disorder caused by certain variation within the brain. Others may define it by what it looks like or how it is expressed, which again, presents challenges as people with ASD have diverse ranges of symptoms. However, there are certain categories or characteristics of symptoms that are particularly indicative of ASD. For example, expressions of ASD are frequently characterized by challenges with social skills, repetitive behaviors, differences with speech, and nonverbal communication (2). Identifying ASD is important because personalized support and potential treatments can improve day-to-day functions and learning for those living with ASD. ASD is four times more common in those assigned male at birth (AMAB) compared to those assigned female at birth (AFAB) (1). Because symptom expression is unique person to person, the most common and generalized symptoms are often used for identifying ASD.

General presentations of ASD may include: 

  • Difficulties with social interaction and communication

  • Avoiding eye contact

  • Difficulties using and understanding facial expressions

  • Refraining from interacting with others

    • In childhood, this may be noticed during opportunities to play with other children

  • Repetitive behaviors

    • Ex: repeating phrases, following strict routines, having obsessive interests

  • Delayed or absent use of spoken language without a clear physical cause

  • Slower development of movement and learning skills

  • Hyperactive or inattentive behavior

  • Unusual eating habits

  • Gastrointestinal problems

  • Unusual emotional reactions

  • Anxiety (2)

 
 

Differences in Expression

It Is currently estimated that 1 in 44 children in the United States are diagnosed with ASD. It affects people of all races, ethnicities, and socioeconomic groups (1). Some people with ASD may only present with a few symptoms that mildly impact their daily lives, while others may be significantly impacted and require significant support to live independently. While ASD has many degrees of severity, more severe forms of ASD can cause serious cognitive or developmental delays along with non-verbal communication and may require constant outside care. However, many people with ASD live an independent life with minimal support and do not view their ASD as a disability, but rather, feel that their neurodivergence gives them particular strengths. Rachel Nuwer, from Spectrum News, describes a positive benefit of her neurodivergence as “an unusual ability to pay attention to visual and auditory information, directness, or a strong moral compass” (11). This is why ASD is best understood as a spectrum rather than a “one-size-fits-all” diagnosis (3).

People with ASD often face challenges in traditional school settings regardless of their intellectual abilities because most educational environments are structured around neurotypical students. Intellectual capacity can vary dramatically between people with ASD; some fit the criteria for intellectual disability and require constant support, while others have typical or significant intellectual aptitudes along with successful careers. One such person is Elizabeth Bonker, a non-speaking person with ASD who achieved major academic success as Valedictorian at Rollins College in 2022. During her class’s commencement speech, she utilized text-to-speech technology (4).

Gender assignment at birth is another challenge for people living with ASD; ASD can present differently in people who are AFAB compared to those who are AMAB. People AFAB often express signs and symptoms of ASD that are different from “typical” symptoms of ASD. How aware a provider is of a condition and its symptoms directly impacts early and accurate diagnoses. The diverse symptoms of ASD, unfortunately, widens the gap in provider awareness which can delay the time to diagnosis.

ASD is primarily diagnosed in a specialist’s office without invasive testing, however, there are benefits to using genetic testing. Current genetic testing allows scientists to view the specific genetic code of a person’s entire exome, the portion of DNA that specifically codes for genes, or the whole genome, which includes both the exome and the regions of DNA that do not code for genes, but rather support their regulation or other processes. These test options are called Whole Exome Sequencing (WES) or Whole Genome Sequencing (WGS). Through analyzing all sequenceable DNA from a large number of DNA samples, researchers have identified links between specific genetic changes and ASD.

Finding these genetic changes is not aimed to “cure” an individual’s neurodivergence, but rather, to address possible unwanted symptoms or neurological complications, like seizures, anxiety, depression, and others that may be caused by specific genetic changes(19).

Read Part Two: Genetics of ASD

 
 

Citations

1. CDC. “Signs & Symptoms | Autism Spectrum Disorder (ASD) | NCBDDD | CDC.” Centers for Disease Control and Prevention, 28 Mar. 2022, https://www.cdc.gov/autism/signs-symptoms/?CDC_AAref_Val=https://www.cdc.gov/ncbddd/autism/signs.html

2.  “Autism Spectrum Disorder.” National Institute of Mental Health (NIMH), https://www.nimh.nih.gov/health/topics/autism-spectrum-disorders-asd Accessed 16 Aug. 2022. 

3. Nightengale, Laura. “The Autism Spectrum Explained.” OSF HealthCare Blog, 26 June 2019, https://www.osfhealthcare.org/blog/the-autism-spectrum-explained/.

4. Chappell, Bill. “A Nonspeaking Valedictorian with Autism Gives Her College’s Commencement Speech.” NPR, 12 May 2022. NPR, https://www.npr.org/2022/05/12/1098506522/nonspeaking-valedictorian-autism-college-commencement-speech

5. Autism Spectrum Disorder: MedlinePlus Genetics. https://medlineplus.gov/genetics/condition/autism-spectrum-disorder/ Accessed 21 June 2022.

6. William M. Brandler et al. ,Paternally inherited cis-regulatory structural variants are associated with autism. Science360,327-331(2018). https://www.science.org/doi/10.1126/science.aan2261

7. CDC. “Autism Spectrum Disorder, Family Health History, and Genetics” Reviewed May 18, 2022.  https://www.cdc.gov/autism/about/index.html

8. FirespringInt. “Seven Disorders Closely Related to Autism.” Autism Research Institute, https://www.autism.org/related-disorders/ Accessed 1 Aug. 2022.

9. Autism | NAMI: National Alliance on Mental Illness. https://www.nami.org/Learn-More/Mental-Health-Conditions/Related-Conditions/Autism. Accessed 1 Aug. 2022.

10. BSc, Andréas RB Deolinda, BA. “Is There Genetic Testing For Autism?” Autism Parenting 

Magazine, 29 Sept. 2021, https://www.autismparentingmagazine.com/autism-genetic-testing/ 

11. “Finding Strengths in Autism.” Spectrum | Autism Research News, 12 May 2021, 

https://www.spectrumnews.org/features/deep-dive/finding-strengths-in-autism/

12. “There’s No Autism Epidemic. But There Is an Autism Diagnosis Epidemic.” STAT, 10 Feb. 2022, https://www.statnews.com/2022/02/10/theres-no-autism-epidemic-but-there-is-an-autism-diagnosis-epidemic/.

13. Americans With Disabilities Act of 1990, 42 U.S.C. § 12101 et seq. (1990). https://www.dol.gov/general/topic/disability/ada 

14. Oxford Languages and Google - English | Oxford Languages. https://languages.oup.com/google-dictionary-en/  Accessed 31 July 2022.

15. “LGBTQ Inclusion: Glossary.” UW Medicine, https://www.uwmedicine.org/provider-resource/lgbtq/lgbtq-inclusion-glossary Accessed 31 July 2022.

16. “What You Need to Know About Nonspeaking Autism.” Healthline, 1 Nov. 2021, https://www.healthline.com/health/autism/nonverbal-autism.

17. Nonverbal Autism: Symptoms, Diagnosis, and Treatment. 22 Nov. 2021, https://www.medicalnewstoday.com/articles/non-verbal-autism 

18. Definition of EXOME. https://www.merriam-webster.com/dictionary/exome  Accessed 31 July 2022.

19. Autism Spectrum Disorder (ASD) Screening. MedlinePlus Genetics. https://medlineplus.gov/lab-tests/autism-spectrum-disorder-asd-screening/ Accessed 18 January 2024.