Meyahealth
Home
ENES
HomeGeneticsGeneNBEAL2 gene
Back to Gene

NBEAL2 gene

Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

NBEAL2 gene

The NBEAL2 gene provides instructions for making a protein critical for the development of platelets, the blood cells responsible for clotting.

Normal Function

The NBEAL2 gene provides instructions for making a protein whose function is unclear. The protein appears to be critical for the normal development of platelets, which are small blood cells involved in blood clotting.

Platelets are produced in bone marrow, the spongy tissue in the center of long bones that produces most of the blood cells the body needs. Platelets are formed from large precursor cells known as megakaryocytes. Within these cells, the NBEAL2 protein is thought to play a role in the development of sacs called alpha-granules, which are the most abundant components of platelets. Alpha-granules contain growth factors and other proteins that are important for blood clotting and wound healing. In response to an injury that causes bleeding, the proteins stored in alpha-granules help platelets stick to one another to form a plug that seals off damaged blood vessels and prevents further blood loss.

Health Conditions Related to Genetic Changes

Gray platelet syndrome

At least 35 mutations in the NBEAL2 gene have been found to cause gray platelet syndrome, a disorder associated with abnormal bleeding. Most people with gray platelet syndrome also develop a condition called myelofibrosis, which is characterized by the buildup of scar tissue (fibrosis) in the bone marrow that prevents it from making enough normal blood cells.

Mutations in the NBEAL2 gene disrupt the normal production of alpha-granules in megakaryocytes. Without alpha-granules, platelets are abnormally large and fewer in number than usual (macrothrombocytopenia). The abnormal platelets also appear gray when viewed under a microscope, which gives this condition its name. A lack of alpha-granules impairs the clumping of platelets in response to injury, increasing the risk of abnormal bleeding. Myelofibrosis is thought to occur because the growth factors and other proteins that are normally packaged into alpha-granules leak out into the bone marrow. The proteins lead to fibrosis that affects the bone marrow's ability to make new blood cells.

Other Names for This Gene

  • BDPLT4
  • GPS
  • KIAA0540
  • neurobeachin-like 2
  • neurobeachin-like protein 2

Frequently Asked Questions

Patients with gray platelet syndrome often experience easy bruising, prolonged nosebleeds, heavy menstrual periods, and bleeding after minor cuts or dental work. In severe cases, spontaneous bleeding into joints or the gastrointestinal tract can occur. If you notice any of these signs, ask your doctor for a platelet count and a platelet morphology test.
Management focuses on preventing and controlling bleeding. Platelet transfusions are used for severe bleeding or before surgery. Antifibrinolytic agents (e.g., tranexamic acid) can help reduce bleeding in mucosal sites. Because the platelets are dysfunctional, routine antiplatelet drugs (aspirin, clopidogrel) are usually avoided unless medically indicated.
The diagnosis is made by a combination of a low platelet count, large platelet size on a blood smear, and a characteristic lack of alpha‑granules seen with electron microscopy. Genetic testing for pathogenic NBEAL2 variants is also required to confirm the diagnosis.
Many patients develop myelofibrosis, a scar tissue buildup in the marrow that can impair blood cell production. Regular complete blood counts and, if indicated, a bone‑marrow aspirate or biopsy are used to monitor fibrosis progression. Early detection allows for timely interventions such as growth factor support or, in advanced cases, stem‑cell transplantation.===
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.