Hereditary alpha tryptasemia syndrome

Hereditary Alpha Tryptasemia Syndrome or hereditary α-tryptasemia syndrome or HATS is a genetic and multi-systemic disease caused by an increased copy number α-tryptase-encoding regions on the TPSAB1 (TPSAB1) gene.

Hereditary alpha tryptasemia/familial hypertryptasemia
Hereditary alpha tryptasemia (HAT) or familial hypertryptasemia (FHT) is common in the general population, affecting around 1 in 20 people, and is often asymptomatic.

Hereditary alpha tryptasemia syndrome (HATS) is only diagnosed when a cluster of associated symptoms are also present.

Signs and symptoms
Hereditary Alpha Tryptasemia Syndrome symptoms include:
 * a high baseline tryp­tase level (over 8 μg/L or over 11, depending on the criteria used)
 * joint pains
 * gastroesophageal reflux disease (GERD)
 * flushing
 * urticaria
 * joint hypermobility
 * postural orthostatic tachycardia syndrome (POTS)
 * increased risk of anaphylaxis (serious allergic reaction) to stinging insects such as bees
 * irritable bowel syndrome (IBS)