Protocol Number: 04-HG-0226

Title:

Investigations of Megakaryocytes from Patients with Abnormal Platelet Vesicles

Number:

04-HG-0226

Summary:

This study will obtain and analyze megakaryocytes (bone marrow cells that mature into blood platelets) to learn more about bleeding disorders that result from defective blood platelets. Platelets are small blood cells that form plugs, or blood clots, on injured blood vessels to stop bleeding. Platelets have sacs that contain proteins and other substances that help form these clots. People with abnormal or missing platelet sacs tend to bleed longer than other people because their platelets lack these chemicals. This study will examine how megakaryocytes build platelet sacs and what may go wrong to cause bleeding disorders associated with defective platelet sacs.

Patients 2 through 80 years of age with the following disorders may be eligible for this study: gray platelet syndrome; Hermansky-Pudlak syndrome; isolated -storage pool deficiency; combined -storage pool deficiency; Chediak-Higashi syndrome; Griscelli syndrome, Wiskott-Aldrich syndrome; and thrombocytopenia absent radium syndrome.

Participants are admitted to the Clinical Center for 3 to 5 days under another NIH protocol for diagnostic and treatment evaluations. For this study, patients also have a blood sample drawn and a bone marrow aspiration. For the aspiration, the patient is sedated and the area above the hip bone is numbed. A thin needle is inserted into the bone, and 1 to 2 teaspoons of bone marrow is withdrawn through the needle. If the aspiration is not successful, a biopsy is done during the same session, using a larger needle to obtain the marrow.

The bone marrow sample is used for routine diagnostic studies and to cull stem cells, which are grown into megakaryocytes for testing, including genetic studies.

Sponsoring Institute:

National Human Genome Research Institute (NHGRI)

Recruitment Detail

Type: Active Accrual Of New Subjects

Gender: Male & Female

Referral Letter Required: No

Population Exclusion(s): None

Eligibility Criteria:

INCLUSION CRITERIA:

This protocol will include children and adults with a clinical diagnosis of GPS, HPS, isolated gamma-SPD, combined alpha gamma-SPD, Griscelli disease, Chediak Higashi syndrome, Wiskott Aldrich syndrome or Thrombocytopenia absent radius syndrome. Patients whose platelets exhibit abnormal intracellular vesicle morphology will also be eligible.

EXCLUSION CRITERIA:

Patients younger than 2 years and older than 80 years will be excluded. Patients with severe thrombocytopenia (fewer than 20 X 10(12) platelets/L) will be excluded.

Special Instructions: Currently Not Provided

Keywords:

Gray Platelet Syndrome

Hermansky-Pudlak Syndrome

Storage Pool Deficiency

Organelle Formation

Megakaryocyte Development

Megakaryocytes

Platelets

Dense Granules

Alpha Granules

Lysosome-related Organelles

Recruitment Keywords:

Gray Platelet Syndrome

GPS

Hermansky-Pudlak Syndrome

HPS

Griscelli Disease

Chediak Higashi Syndrome

Wiskott Aldrich Syndrome

Platelet

Congenital Bleeding Disorders

Conditions:

Investigational Drug(s):

None

Investigational Device(s):

None

Contacts:

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citations:

Rendu F, Brohard-Bohn B. The platelet release reaction: granules' constituents, secretion and functions. Platelets. 2001 Aug;12(5):261-73. Review. PMID: 11487378

White JG. Ultrastructural studies of the gray platelet syndrome. Am J Pathol. 1979 May;95(2):445-62. PMID: 453324

McNicol A, Israels SJ. Platelet dense granules: structure, function and implications for haemostasis. Thromb Res. 1999 Jul 1;95(1):1-18. Review. PMID: 10403682

• Questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
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Bethesda, Maryland 20892. Last update: 10/21/2004