Research on Tourette’s indicates that the condition is strongly influenced by inherited genetic factors, with environmental factors also contributing to its development.

Tourette syndrome is a neurodevelopmental disorder that causes repetitive, involuntary movements and sounds, known as tics.

It often runs in families, suggesting a strong genetic influence, though researchers are still studying how genetics and other factors contribute to its development.

Let’s examine how Tourettes and genetics are connected and if environmental factors might affect its development.

Research shows that Tourette syndrome often runs in families. However, the genetic causes are not simple, as they involve multiple genes interacting with each other and environmental factors.

A 2022 study found that Tourette syndrome is “polygenic,” meaning many genes are involved. And while changes in dopamine and serotonin systems, which control mood and movement, may also play a role, research hasn’t established a clear link yet.

Even with these advances, the exact genetic causes are still unclear. Researchers estimate that Tourette syndrome is about 70% to 80% heritable, meaning genetics play a significant role, but more research is needed to understand how it works.

The National Institute of Neurological Disorders and Stroke (NINDS) notes that several genes may be involved in Tourette syndrome, including:

  • SLITRK1
  • NRXN1
  • CNTN6

A 2023 study review also identified other genes that may be involved, such as:

  • LINC01122
  • DRD2
  • HRH3
  • MAOB
  • BDNF
  • SNAP25
  • SLC6A4

While these genes have links to Tourette syndrome, they may also have links to conditions like ADHD and OCD. However, changes in these genes do not guarantee that a person will develop Tourette syndrome.

Tourette syndrome does not follow a simple inheritance pattern like some genetic conditions. Instead, experts consider it multifactorial, meaning it involves a combination of genetic and nongenetic factors.

Research from 2022 notes that people don’t inherit Tourette syndrome in a purely Mendelian way (passed down directly from one parent). Instead, multiple genes and their interactions may affect the chances of passing it to children.

Your risk of developing Tourette syndrome is higher if you have a first-degree relative (parent, sibling, or child) with the condition. Still, not everyone with a genetic risk will show symptoms, suggesting other factors, like environment, also play a role.

Tourette syndrome is also more common in people assigned male at birth, who are 2 to 10 times more likely to have it than people assigned female at birth. Researchers believe that sex-specific genetic factors may explain this, but more studies are needed.

Certain conditions with a genetic link may occur alongside Tourette syndrome. These include:

  • Obsessive-compulsive disorder (OCD): OCD often co-occurs with Tourette syndrome, as both share similar genetic factors.
  • Attention deficit/hyperactivity disorder (ADHD): ADHD is a common condition seen with Tourette syndrome, with overlapping genetic risks.
  • Autism spectrum disorder (ASD): While not directly linked, research shows some shared genetic traits between Tourette syndrome and ASD.

The Centers for Disease Control and Prevention (CDC) states that no single test, such as a genetic test, can diagnose Tourette syndrome.

Although genetic testing is not a common test for Tourette syndrome in clinical practice, certain tests can identify genes linked to the condition, such as:

  • Whole exome sequencing (WES): This test helps identify changes in genes, like SLITRK1 or HDC, that may have links to Tourette syndrome.
  • Chromosomal microarray analysis (CMA): This test checks for missing or extra parts of chromosomes that could affect genes related to Tourette syndrome.

These tests are primarily used in research or when Tourette syndrome occurs alongside other genetic or neurodevelopmental conditions.

While no routine genetic test for Tourette syndrome is available yet, future advances in genetics may improve diagnosis.

If you’re considering genetic testing, consider talking with a healthcare professional or genetic counselor to understand its benefits and limitations.

While genetics are the primary contributor to Tourette syndrome, other factors may increase the risk, including:

  • Prenatal and perinatal factors: Complications during pregnancy, low birth weight, and smoking while pregnant may increase the risk.
  • Sex assigned at birth: Males are more likely to develop Tourette syndrome than females.
  • Environmental influences: Exposure to infections, toxins, or stressors may interact with genetic predispositions to trigger symptoms.
  • Ethnicity: Tourette syndrome diagnoses are more common in white people compared to Black or Hispanic populations.

At what age do symptoms of Tourette syndrome appear?

Symptoms typically begin between ages 5 to 10, with motor tics often preceding vocal tics. The severity usually peaks in the early teenage years and may improve in adulthood.

Can you get Tourette syndrome if your parents don’t have it?

Yes, while Tourette syndrome often runs in families, it can occur without a direct family history due to spontaneous genetic mutations or nongenetic factors.

Is Tourette syndrome a form of autism?

No, Tourette syndrome is not a form of autism. However, the two conditions can co-occur, and they may share some genetic pathways and traits.

Genetics has a significant influence on the development of Tourette syndrome, but other factors can also contribute. While no single gene causes the condition, ongoing research is continuing to identify important genetic links and how they interact.

If you or someone you know has Tourette syndrome, consider talking with a healthcare professional for support and personalized care. Genetic counseling can also help families understand risks and make informed care decisions.