3q29 Deletion Syndrome, Mental Health and Autism: Results From the 3q29 Registry

When you first get your 3q29 deletion diagnosis, you may see autism on the list of developmental and psychiatric conditions that can come along with it.

In fact, 3q29 deletion has been shown in previous studies to be associated with:

  • Nearly universal developmental delay or intellectual disability

  • 20-40 times higher risk for schizophrenia

  • Generalized anxiety disorder, attention deficit disorder (ADHD), bipolar disorder

  • 19 times higher risk for autism spectrum disorder (ASD)

Up to now, there has been little information about how ASD impacts folks with 3q29 deletion.

To answer this question, the 3q29 Project put together the largest study to date to learn more about ASD with 3q29 deletion in order to better help families and care teams understand how to treat and support folks with 3q29 deletion.

You can read the full study here or continue reading the overview below.

About the Study

We know that 3q29 deletion is associated with neurodevelopmental and psychiatric conditions, particularly with an increased risk for autism spectrum disorder (ASD). This study sought to learn more about:

  • How common ASD is in the 3q29 deletion population

  • How 3q29 deletion ASD compares to idiopathic ASD (meaning autism in people who don’t have another underlying health condition)

  • How people with 3q29 deletion WITH or WITHOUT an ASD diagnosis are affected

  • How ASD with 3q29 deletion compares to other genetic syndromes

Through the 3q29 registry, the study recruited 93 participants with 3q29 deletion and compared them to controls. Information was obtained through questionnaires completed by the study participants or their caregivers.

Questionnaires included a customized medical and demographic questionnaire, and four  standardized questionnaires used to look at ASD symptoms and general behavioral problems:

  • The Social Responsiveness Scale

  • The Social Communication Questionnaire

  • The Autism Spectrum Screening Questionnaire

  • The Child Behavior Checklist

What the Study Found

Research found that compared to the control group, those in the 3q29 deletion group had higher rates of autism, but with characteristics that set them apart.

  • 29% of 3q29 deletion participants had an ASD diagnosis (compared to 1.47% of the control group).

  • 3q29 deletion increases the risk of ASD in girls more than in boys. (Typically, the rate of girls to boys with ASD is 1 to 4, but with 3q29 deletion the rate is 1 to 2.)

  • The 71% of 3q29 participants who did not have an ASD diagnosis still showed signs of significant social disability.

  • Folks with 3q29 deletion and ASD had only mildly impaired social motivation, while rates of restricted interests and repetitive behaviors were high. (By comparison, impairment is usually equal across all the scales in idiopathic autism.)

The researchers ruled out heart defects and intellectual disability as the causes of increased social disability in the 3q29 deletion participants. They found that ASD and social disability occurs  just as often in people with 3q29 deletion with or without heart defects or intellectual disabilities. This points to the genetic deletion being the root cause.

There are other genetic syndromes associated with increased risks for ASD. However, in comparison, 3q29 deletion has a unique presentation of symptoms.  This study also indicates that 3q29 deletion is at the high end of increasing risk.

What it Means

Here are some take-aways:

  • 3q29 deletion raises the risk of ASD even higher in girls than in boys. (There is no significant difference in how ASD looks among girls and boys without 3q29 deletion.)

  • People with 3q29 deletion and NO ASD diagnosis still live with significant rates of social disability (although not as high as those with the ASD diagnosis). This is probably because some people haven’t gotten the right ASD diagnosis yet, but also because 3q29 deletion increases social disability across the board.

  • People with 3q29 deletion maintain high rates of social motivation compared to idiopathic autism. Despite their social disabilities, they really want to be social and friendly. This means that therapies to teach social skills, such as cognitive behavioral therapy, can be especially helpful.

High-quality evaluation for ASD and social disability, along with social skill-building therapies, should be the standard of care for people with 3q29 deletion syndrome.

It is very important for people with 3q29 deletion to be evaluated for ASD by qualified professionals using gold standard diagnostic measures. Even those without ASD diagnoses should be evaluated for social disability. Therapy to build social skills should be helpful to folks with 3q29 deletion, with or without ASD diagnoses, and their motivation to be social is an important strength to build on.