Hereditary Alpha Tryptasemia (HAT): What It Is and Its Link to POTS & Joint Issues

science & research May 29, 2024
for the image above can you give an seo alt text

Have you heard of Hereditary Alpha Tryptasemia (HAT)? This genetic trait leads to higher levels of tryptase, an enzyme released by immune cells called mast cells.

While HAT is relatively common, it's often misunderstood and can be linked to complex conditions like MCAS, POTS, and hypermobility. Let's unravel what HAT is and isn't.

HAT Basics

  • Genetics: HAT is caused by extra copies of the alpha-tryptase gene. Around 6% of people have it, but not everyone experiences symptoms.
  • Elevated Tryptase: The hallmark is elevated blood tryptase levels. However, other conditions can also raise tryptase.
  • MCAS Connection: Some people with HAT also have Mast Cell Activation Syndrome (MCAS), a disorder where mast cells release too many inflammatory substances.

The POTS and Hypermobility Questions

  • Possible Link to Dysautonomia: Some HAT patients show signs of dysautonomia (nervous system dysfunction), including abnormal tilt table test results suggestive of POTS.
  • No Increased Prevalence: While a connection is possible in individuals, HAT itself doesn't seem more common in those with POTS or hypermobility.
  • Unique Features: People with both HAT and POTS may be more likely to experience difficulty swallowing and delayed shedding of baby teeth.

Busting HAT Myths

  • HAT Doesn't Explain Everything: Because HAT is common, some symptoms might be wrongly attributed to it. It's crucial to consider other possible diagnoses.
  • Not Everyone with HAT is Symptomatic: Having this genetic trait doesn't guarantee health problems.


HAT is a complex piece of the health puzzle. Understanding its connections to other conditions, potential symptoms, and limitations is crucial for accurate diagnosis and management.

If you have concerns about HAT, consulting a specialist in allergy and immunology is recommended.

Do you have HAT or know someone who does? Have you been tested for tryptase level elevations? Share your experiences in the comments.


Q: How do I get tested for HAT? A blood test measures your tryptase levels and specific gene analysis confirms HAT as the cause of elevated tryptase.

Q: Does having HAT mean I will develop POTS? No, most people with HAT do not develop POTS. However, there's a subset with both HAT and MCAS who may be at higher risk.

Q: Can treating HAT improve my POTS symptoms? It's unlikely. While some MCAS treatments might overlap with POTS management, it depends on the underlying causes of your POTS. Addressing all contributing factors is essential.

Additional Resources

Read More Posts

See All Posts

IBS: More Than Just a Gut Feeling

May 01, 2024