Familial erythrocytosis type 2 commonly known as Chuvash erythrocytosis, is a disease where people have too many red blood cells in their blood. Red blood cells are the part of the blood that carry oxygen throughout the body. There is a special protein called erythropoietin that tells the body to make red blood cells. In people with type 2 familial erythrocytosis, their bodies make too much erythropoietin. This leads to an excess of red blood cells.
People may have very few symptoms of this disease in the early stages of life, but they may experience headaches, dizziness, nosebleeds, and shortness of breath. They may also have a red/ruddy complexion due to the increased concentration of red blood cells in the blood. During adulthood, people with type 2 familial erythrocytosis are at increased risk for blood clots, which happen when the red blood cells get “stuck” and cannot pass through the veins or arteries. These blood clots can cause heart attacks or strokes. However, some people may only experience mild symptoms.
Familial erythrocytosis 2 is caused by a change (mutation) in the VHL gene. This gene makes a complex that helps regulate erythropoietin production. When the gene is not working correctly, this leads to too much erythropoietin and too many red blood cells. The gene is inherited in an autosomal recessive pattern. This means that the person needs to inherit two copies of the mutated gene, one from each parent, to get the disease. Their parents may be unaffected carriers.
Type 2 familial erythrocytosis is usually suspected after performing blood tests that identify increased red blood cell levels. The diagnosis can then be confirmed by genetic tests that look for the VHL mutation. If you or a family member has been diagnosed with familial erythrocytosis type 2, contact your doctor about the most current treatment options. Support groups are also good resources for support and information.
Description Last Updated: Jan 15, 2018