A geneticist and a BCBA answer two different questions, and knowing that distinction is the first step in deciding whether genetic testing makes sense for your family. Genetic testing does not diagnose autism, and a negative result does not mean your child is somehow less autistic than a child whose test comes back positive. 

What it can do is answer a separate, worthwhile question: is there an identifiable reason behind this diagnosis, and does that reason change anything else about your child’s medical care.

This question tends to come up in the same conversation as an autism diagnosis itself, often before a family has even started ABA therapy. At Achieve ABA Therapy Group, we are not the ones who order or interpret genetic testing, that is a pediatrician’s, developmental pediatrician’s, or geneticist’s job, but we get asked about it often enough that it is worth laying out plainly: what the testing actually looks for, what it can and cannot tell you, and how families typically make this decision.

In short: genetic testing after an autism diagnosis looks for an underlying medical cause, not autism itself, finds an identifiable answer in a minority of cases, and does not need to happen before starting ABA therapy.

What Genetic Testing Looks For After an Autism Diagnosis

Genetic testing for autism is not one single test. It is usually a short sequence, starting broad and narrowing based on what your child’s doctor finds during an exam and family history review.

Chromosomal Microarray, the First Test Most Doctors Recommend

Chromosomal microarray analysis, often shortened to CMA, looks for missing or duplicated pieces of chromosomes too small to see under a microscope. It is the test the American Academy of Pediatrics has identified as a reasonable first step for a child with autism, and it identifies a genetic cause in roughly one in five cases tested.

Fragile X Testing and Other Targeted Tests

Fragile X syndrome is the most common inherited cause of intellectual disability linked to autism, though it turns up in under one percent of children tested for it. If your child’s exam points toward a specific condition, tuberous sclerosis or Rett syndrome, for example, your doctor may order a more targeted test instead of, or alongside, chromosomal microarray.

What Genetic Testing Can and Cannot Tell You About Autism

This is the part that surprises a lot of parents. Genetic testing does not diagnose autism, and it was never designed to.

An Autism Diagnosis Comes From Behavior, Not a Lab Result

Autism is diagnosed through observation and standardized assessment, watching how a child communicates, plays, and interacts, not through a blood draw. A clean genetic test does not rule autism out, and a genetic finding does not make an autism diagnosis more or less real.

Why Most Results Come Back Without a Clear Answer

Even with the most thorough testing currently available, most children with autism do not get an identifiable genetic cause. That does not mean genetics play no role. Twin studies point to a strong hereditary component, but for most families, no single test available today will point to one specific reason.

Why a Pediatrician or Geneticist Might Still Recommend It

If testing will not diagnose autism and usually will not find an answer, it is fair to ask why doctors recommend it at all. The reasons have less to do with autism itself and more to do with everything else it can catch.

Catching a Medical Condition That Needs Its Own Monitoring

Some genetic conditions linked to autism come with medical needs of their own, seizure risk with tuberous sclerosis, for example, or heart and connective tissue concerns with certain chromosomal conditions. Finding this early means a doctor can start monitoring for it before it becomes a bigger problem.

Family Planning and Recurrence Risk

For parents considering more children, or for adult siblings thinking about their own families, a genetic finding can bring real information about the odds of it happening again. A genetic counselor is the right person to walk through what a specific result does and does not mean for future pregnancies.

Should Genetic Testing Delay the Start of ABA Therapy?

No, and this is worth saying directly, because it is one of the most common points of confusion we see.

Genetic testing can take weeks to months to come back, and results have no bearing on whether your child is ready to start building communication, play, and daily living skills. If your family is deciding between scheduling a genetics appointment and starting therapy, the honest answer is to do both. Our first 90 days after an autism diagnosis guide covers how to sequence everything else that tends to pile up in that window.

Our plain-language explanation of what ABA is is also a good starting point if genetic testing is the first appointment on your calendar and ABA still feels like an unknown.

Where Colorado Families Go for Genetic Testing and Counseling

Genetic testing itself is ordered by a physician, not an ABA provider, so pursuing it usually means a referral outside your child’s therapy team.

Children’s Hospital Colorado’s genetic counseling program is the most comprehensive pediatric option in the Denver metro area, and it specifically lists autism and developmental delay among the concerns it evaluates, with both in-person and telehealth appointments available. Ask your pediatrician for a referral, or your developmental pediatrician if you already have one.

If your child is under three and already receiving early intervention services in Colorado, your service coordinator can often help connect you to a referral as part of that broader team.

Wherever you are in Colorado, from Denver and Aurora to Colorado Springs, Fort Collins, or a smaller Front Range community, this decision does not change how our team supports your family day to day. 

We work with families across Lakewood, Thornton, Arvada, Westminster, Centennial, Boulder, Greeley, Longmont, Loveland, Broomfield, Castle Rock, Parker, Englewood, and Pueblo, and a genetics referral is simply one more piece of the puzzle, not a detour from the plan already in place.

What Genetic Testing Costs and Who Pays for It

Genetic testing is billed separately from ABA therapy, through your child’s medical insurance rather than through your ABA provider, and costs vary widely depending on which tests are ordered.

Most major insurance plans, including Health First Colorado, cover genetic testing when a physician documents medical necessity, though prior authorization is common. If you are sorting out coverage for therapy at the same time, our breakdown of what Health First Colorado covers for ABA therapy and our full guide to ABA therapy costs in Colorado explain how that separate process works.

Ask the testing lab directly about self-pay pricing if you are uninsured or a claim gets denied. Many labs offer a reduced cash rate that is not advertised upfront.

Making the Decision as a Family

There is no universally right answer here, and no ethical provider should pressure you either way. A few honest questions worth sitting with:

• Would knowing a specific cause change how you approach future medical appointments
• Are you considering more children and want recurrence-risk information now rather than later
• Does the emotional weight of an inconclusive result, the most likely outcome, feel manageable right now, or better saved for later
• Do your child’s exam findings, unusual features, seizures, a strong family history, make your doctor especially confident testing will find something

Some families want every answer available immediately. Others want a few months into therapy before adding another appointment to the calendar. Both are reasonable, and this is a decision you can revisit later if it does not feel right to pursue today.

There Is No Wrong Choice Here

Genetic testing after an autism diagnosis is optional, personal, and separate from the therapy decisions already in front of you. Whether your family pursues it immediately, later, or not at all, it will not change your child’s need for support, or your ability to get it.

If you are navigating a recent diagnosis and are not sure what to prioritize first, our Colorado team is glad to help you sort out what comes next. 

Frequently Asked Questions About Genetic Testing and Autism

Does insurance require genetic testing before covering ABA therapy?

No. ABA therapy coverage is based on your child’s autism diagnosis and a documented treatment plan, not on genetic test results. You do not need to pursue or complete genetic testing to start or continue therapy.

What percentage of autism cases have an identifiable genetic cause?

It varies by which tests are used, but chromosomal microarray alone identifies a cause in roughly 15 to 20 percent of cases. Most children with autism do not receive a specific genetic answer, even with thorough testing.

Can genetic testing tell us if our next child will also be autistic?

Sometimes, but not always. If a specific genetic cause is identified, a genetic counselor can often estimate recurrence risk. If no cause is found, which is the more common outcome, that specific estimate usually is not available.

Who orders genetic testing for autism, a pediatrician or a geneticist?

Either can, depending on your child’s situation. Many pediatricians order first-tier testing like chromosomal microarray directly, then refer to a geneticist or genetic counselor if results are unclear or a specific condition is suspected.

Will a genetic diagnosis change my child’s ABA treatment plan?

Usually not directly. Your child’s ABA goals are based on individual skills and needs, not genetic results. A genetic diagnosis is more likely to add medical monitoring or specialist referrals alongside therapy, rather than change the therapy itself.

Sources:

• American Academy of Pediatrics. (2022). The role of genetic testing among autistic individuals. Pediatrics. https://publications.aap.org/pediatrics/article/149/Supplement%204/e2020049437L/185639/The-Role-of-Genetic-Testing-Among-Autistic
• American Academy of Pediatrics. (2020). Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. https://publications.aap.org/pediatrics/article/145/1/e20193447/36917/Identification-Evaluation-and-Management-of
• National Library of Medicine, MedlinePlus Genetics. (n.d.). What is genetic testing? https://medlineplus.gov/genetics/understanding/testing/genetictesting
• Children’s Hospital Colorado. (n.d.). Genetic counseling services. https://www.childrenscolorado.org/doctors-and-departments/departments/genetics/genetic-counseling-services/
• Centers for Disease Control and Prevention. (2025). Data and statistics on autism spectrum disorder. https://www.cdc.gov/autism/data-research/index.html