NCT00230165 · Rockefeller University
The Genetics and Functional Basis of Inherited Platelet, White Blood Cell, Red Blood Cell, and Blood Clotting Disorders.
What this study is about
Blood contains red blood cells, white blood cells, and platelets, as well as a fluid portion termed plasma. We primarily study blood platelets, but sometimes we also analyze the blood of patients with red blood cell disorders (such as sickle cell disease), white blood cell disorders, and disorders of the blood clotting factors found in plasma.
View original scientific description
Blood contains red blood cells, white blood cells, and platelets, as well as a fluid portion termed plasma. We primarily study blood platelets, but sometimes we also analyze the blood of patients with red blood cell disorders (such as sickle cell disease), white blood cell disorders, and disorders of the blood clotting factors found in plasma. Blood platelets are small cell fragments that help people stop bleeding after blood vessels are damaged. Some individuals have abnormalities in their blood platelets that result in them not functioning properly. One such disorder is Glanzmann thrombasthenia. Most such patients have a bleeding disorder characterized by nosebleeds, gum bleeding, easy bruising (black and blue marks), heavy menstrual periods in women, and excessive bleeding after surgery or trauma. Our laboratory performs advanced tests of platelet function and platelet biochemistry. If we find evidence that a genetic disorder may be responsible, we analyze the genetic material (DNA and RNA) from the volunteer, and when possible, close family members to identify the precise defect.
Primary outcome measures
Platelet aggregation
Time frame: minutes
The initial slope of the increase in light transmission after an agonist is added to a cuvette containing platelet-rich plasma.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- A. Normal Healthy Volunteers:
- Normal healthy volunteers
- 18 years of age or older
- Any ethnic background. B. Patients with Glanzmann thrombasthenia or their relatives, inherited qualitative and/or quantitative platelet disorders, inherited disorders of white blood cells, inherited disorders of coagulation (including von Willebrand disease):
- Adults and children
- Any ethnic background
Exclusion criteria
- A. Normal Healthy Volunteers:
- For studies of platelets that may be affected by anti-platelet therapy, ingestion of aspirin or similar medication in the past week.
- Having given blood in the last 8 weeks such that the current donation would exceed a total of 250 ml for the 8 week period.
- Having given blood in the past week such that this donation would result in more than 2 donations in one week. B. Patients with Glanzmann thrombasthenia or their relatives, inherited qualitative and/or quantitative platelet disorders, inherited disorders of white blood cells, inherited disorders of coagulation (including von Willebrand disease).
- For studies of platelets that may be affected by antiplatelet therapy, ingestion of aspirin or similar medication in the past week
- If the patient is known to have a hematocrit ≥25 (assay performed in past 3 months), the same blood drawing criteria as in A, with the addition that for children less than 18 years of age, the maximum amount of blood allowed to be donated in an 8 week period is the lesser of 50 ml or 3 ml/kg.
- If the patient has a hematocrit \<25 or if the hematocrit is unknown, the blood drawing limit is the lesser of 20 ml or 1 ml/kg in any 8 week period.
Where
- New York, New York
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 20, 2025 · Source of record for eligibility and locations