Autism Diagnosing Criteria Often Overlooks Those With Genetic Conditions

An international study conducted out of the U.K. by Cardiff University shows that many people with genetic conditions and autism symptoms cannot easily get a formal autism diagnosis. Specifically, people with copy number variant (CNV) genetic conditions often don’t meet the criteria necessary to access many autism services and resources.

The study, which looked at 547 people previously diagnosed with one of four genetic conditions that are associated with a high incidence of autism, found that 23% to 58% of participants also presented with autism symptoms (social and communication difficulties and/or repetitive behaviors). Comparatively, the prevalence of autism in the general public is only 1%.  

“A child may have clinically significant symptoms, but not meet formal autism criteria,” Samuel JRA Chawner, PhD, co-author of the study, and research scientist with MRC Centre for Neuropsychiatric Genetics and Genomics at Cardiff University, tells Verywell via email. “Families in this situation currently receive very little support.”

Genetic Conditions Associated with Autism Symptoms 

According to the National Human Genome Research Institute (NIH), CNV occurs when there is a variation in the number of copies of certain genes expressed in DNA from person to person. The gains and losses of genetic material has been associated with an increased risk in certain diseases and conditions, including autism, although research is ongoing. 

This particular study included people carrying one of the following categorized CNVs:

• 16p11.2 deletion
• 16p11.2 duplication
• 22q11.2 deletion
• 22q11.2 duplication

According to Chawner, the prevalence of autism in certain genetic conditions can range from 11% to 61% .

“In terms of autism symptoms, previous studies have tended to focus on autism diagnosis rather than symptoms,” Chawner says. “Our study indicates that clinically important symptoms are very prevalent, even in those children who do not formally meet autism criteria.”

Autism Spectrum Disorder Diagnosis Criteria

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) outlines the specific criteria physicians must use to make a formal autism spectrum disorder (ASD) diagnosis:

1. Persistent deficits in social communication and social interaction across multiple contexts
2. Restricted, repetitive patterns of behavior, interests, or activities
3. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities or may be masked by learned strategies in later life)
4. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning
5. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay 

The Centers for Disease Control and Prevention (CDC) explains that screening for autism and other developmental delays can be conducted by a number of professionals in health care, community, and school settings. Screening tools may include:

• Ages and Stages Questionnaires (ASQ)
• Communication and Symbolic Behavior Scales (CSBS) 
• Parents' Evaluation of Developmental Status (PEDS) 
• Modified Checklist for Autism in Toddlers (MCHAT) 
• Screening Tool for Autism in Toddlers and Young Children (STAT)

Early Intervention is Key

There is currently not a cure for ASD, but the CDC says that support and intervention at an early age is critical to reduce the impact of development delays and to provide skills to help navigate social, emotional, and school settings. That makes more inclusive diagnostic criteria even more essential.

“It is important that families receive support early in their child’s development to give them the best opportunity to reach their potential,” Marianne van den Bree, PhD, senior author of the study, and professor in the division of psychological medicine and clinical neurosciences at Cardiff University, tells Verywell via email. “All too often, families experience barriers such as long waiting lists for diagnostic services that mean the vital opportunity for early support is missed.”

In the U.S., individual states, counties and school districts offer early intervention services as well as special education services up until the age of 22.

• Early intervention services are available for ages 0-3 and can be requested through a state’s early intervention services system. Caregivers do not need a doctor referral to request an evaluation.
• Special education services are available for ages 3-22 and are requested through the child’s designated school district. A doctor referral is not needed to request an evaluation.

Even if a caregiver suspects autism but is unable to get a diagnosis, there are ways to pursue early intervention. For example, a formal ASD diagnosis is not needed for treatment for specific symptoms, such as speech therapy for language delays.