Gray platelet syndrome

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Reviewed September 2014

What is gray platelet syndrome?

Gray platelet syndrome is a bleeding disorder associated with abnormal platelets, which are blood cell fragments involved in blood clotting. People with this condition tend to bruise easily and have an increased risk of nosebleeds (epistaxis). They may also experience abnormally heavy or extended bleeding following surgery, dental work, or minor trauma. Women with gray platelet syndrome often have irregular, heavy periods (menometrorrhagia). These bleeding problems are usually mild to moderate, but they have been life-threatening in a few affected individuals.

A condition called myelofibrosis, which is a buildup of scar tissue (fibrosis) in the bone marrow, is another common feature of gray platelet syndrome. Bone marrow is the spongy tissue in the center of long bones that produces most of the blood cells the body needs, including platelets. The scarring associated with myelofibrosis damages bone marrow, preventing it from making enough blood cells. Other organs, particularly the spleen, start producing more blood cells to compensate; this process often leads to an enlarged spleen (splenomegaly).

How common is gray platelet syndrome?

Gray platelet syndrome appears to be a rare disorder. About 60 cases have been reported worldwide.

What genes are related to gray platelet syndrome?

Gray platelet syndrome can be caused by mutations in the NBEAL2 gene. Little is known about the protein produced from this gene. It appears to play a role in the formation of alpha-granules, which are sacs inside platelets that 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.

Mutations in the NBEAL2 gene disrupt the normal production of alpha-granules. Without alpha-granules, platelets are unusually 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 normal activity of platelets during blood clotting, 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.

Some people with gray platelet syndrome do not have an identified mutation in the NBEAL2 gene. In these individuals, the cause of the condition is unknown.

How do people inherit gray platelet syndrome?

When gray platelet syndrome is caused by NBEAL2 gene mutations, it has an autosomal recessive pattern of inheritance, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene in each cell.

Gray platelet syndrome can also be inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. An affected person often inherits the condition from one affected parent. Researchers are working to determine which gene or genes are associated with the autosomal dominant form of gray platelet syndrome.

Where can I find information about diagnosis or management of gray platelet syndrome?

These resources address the diagnosis or management of gray platelet syndrome and may include treatment providers.

You might also find information on the diagnosis or management of gray platelet syndrome inEducational resources and Patient support.

General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.

To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about gray platelet syndrome?

You may find the following resources about gray platelet syndrome helpful. These materials are written for the general public.

MedlinePlus - Health information (5 links)
Genetic and Rare Diseases Information Center - Information about genetic conditions and rare diseases
Additional NIH Resources - National Institutes of Health
National Heart, Lung, and Blood Institute: What is Thrombocytopenia?
Educational resources - Information pages (6 links)
Patient support - For patients and families (3 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

Genetic Testing Registry - Repository of genetic test information (1 link)
ClinicalTrials.gov - Linking patients to medical research
OMIM - Genetic disorder catalog

What other names do people use for gray platelet syndrome?

BDPLT4
bleeding disorder, platelet-type, 4
deficient alpha granule syndrome
GPS
grey platelet syndrome
platelet alpha granule deficiency
platelet alpha-granule deficiency
platelet granule defect

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about gray platelet syndrome?

Ask the Genetic and Rare Diseases Information Center

Where can I find general information about genetic conditions?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding gray platelet syndrome?

autosomal ; autosomal dominant ; autosomal recessive ; blood clotting ; bone marrow ; cell ; clotting ;deficiency ; enlarged spleen ; fibrosis ; gene ; inheritance ; inherited ; injury ; mutation ;pattern of inheritance ; platelets ; protein ; recessive ; splenomegaly ; surgery ; syndrome ; tissue ;trauma

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

References (5 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.