Hereditary alpha tryptasemia syndrome

Hereditary alpha tryptasemia syndrome is a condition characterized by high blood tryptase levels, and by several symptoms associated with multiple organ systems. These symptoms may include allergic-like symptoms (skin itching, flushing, hives, or anaphylaxis); gastrointestinal symptoms such as bloating, abdominal pain, diarrhea and/or constipation (often diagnosed as irritable bowel syndrome), heartburn, reflux, and difficulty swallowing; connective tissue symptoms such as hypermobile joints and scoliosis (often diagnosed as Ehlers-Danlos syndrome, hypermobile type); heart symptoms such as a racing or pounding heartbeat or blood pressure swings sometimes with fainting (frequently diagnosed as postural orthostatic tachycardia syndrome (POTS); as well as behavioral problems.

The term “hereditary alpha tryptasemia” refers to the trait of having inherited extra copies of the alpha tryptase gene ( TPSAB1), which leads to increased blood levels of trypase. Tryptase is a protein made primarily by mast cells (cells that contribute to allergic responses). When people with hereditary alpha tryptasemia have symptoms the conditions is known as “hereditary alpha tryptasemia syndrome”. People who have few or no symptoms are said to have the trait, and not the syndrome. Treatment is aimed at addressing the specific symptoms and may include anti-allergy medications.

Please visit the National Institute of Allergy and Infectious Diseases to learn more:
Hereditary Alpha Tryptasemia and Hereditary Alpha Tryptasemia Syndrome FAQ