SNP Shot: Genomic Insights

Essential thrombocythemia is defined by a higher-than-normal platelet count (thrombocythemia). Platelets, also known as thrombocytes, are blood cells critical for blood clot formation. Some individuals with essential thrombocythemia experience no symptoms, while others suffer from complications related to the excessive number of platelets.

A frequent complication in individuals with essential thrombocythemia is abnormal blood clotting (thrombosis), which results in many of the condition's characteristic signs and symptoms. Blood clots obstructing blood flow to the brain can lead to strokes or transient ischemic attacks (TIAs), often called mini-strokes. Thrombosis in the legs can manifest as leg pain, swelling, or both. Furthermore, clots can travel to the lungs (pulmonary embolism), obstructing pulmonary blood flow and triggering chest pain and breathing difficulties (dyspnea).

Paradoxically, another complication of essential thrombocythemia is abnormal bleeding, more prevalent in individuals with extremely high platelet counts. This can manifest as nosebleeds, bleeding gums, or gastrointestinal bleeding. The bleeding is believed to result from a deficiency of a specific clotting protein in the blood, although the underlying cause of this protein reduction remains unknown.

Additional signs and symptoms of essential thrombocythemia may include an enlarged spleen (splenomegaly), weakness, headaches, or abnormal skin sensations like burning, tingling, or prickling. Some individuals may also experience episodes of severe pain, redness, and swelling called erythromelalgia, typically affecting the hands and feet.

Inheritance:

The majority of essential thrombocythemia cases are not inherited. Instead, they stem from gene mutations arising in early blood-forming cells after conception. These mutations are classified as somatic mutations. Less frequently, essential thrombocythemia is inherited in an autosomal dominant manner, where only one copy of the mutated gene in each cell is enough to cause the condition. When inherited, the condition is referred to as familial essential thrombocythemia.