Rare Disease

Our commitment to rare disease

By definition, a rare disease is defined as one that affects fewer than 200,000 people in the U.S. While these patient communities may be small, they are mighty. We are proud to partner with members of the rare disease community to hasten the development of life-changing new therapies for the patients that need them most.

Hereditary Xerocytosis

Hereditary xerocytosis is an autosomal dominant genetic disorder of the red blood cells caused by abnormal permeability of critical cations (K+, Ca+). Red blood cells become dehydrated due to loss of potassium and cell water. The fragility of the red cells can lead to a ranging severity of anemia; in some cases, it will lead to severe anemia that requires frequent blood transfusions. Hereditary xerocytosis is also associated with jaundice, fatigue, splenomegaly (swelling of the spleen) and gallstones.

Current Treatments

There is no approved therapy for this disease.


  • Affects an estimated 1 out of 10,000 people
  • Wide spectrum of disease severity
  • Very underdiagnosed condition today