The Genetics and Functional Basis of Inherited Platelet, White Blood Cell, Red Blood Cell, and Blood Clotting Disorders.

October 15, 2025 updated by: Rockefeller University

Studies of Interactions Among Normal and Abnormal Blood Cells, and the Vessel Wall, and Studies of Genetic and Functional Basis of Inherited Platelet, White Blood Cell, Red Blood Cell and Coagulation Disorders

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.

Study Overview

Status

Recruiting

Conditions

Glanzmann Thrombasthenia

Detailed Description

After volunteers and family members agree to participate, they are seen in the Outpatient Research Center by the Principal Investigator or another physician. A detailed history is obtained, a physical examination is performed, and blood is obtained for further tests. Occasionally patients and family members are requested to return for additional tests. If an abnormality is identified with tests conducted in our research laboratory, we advise the volunteer to have the studies repeated in a laboratory certified to conduct tests on patients.

Study Type

Observational

Enrollment (Estimated)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Name: Recruitment Specialist
Phone Number: 1-800-782-2737
Email: rucares@rockefeller.edu

Study Locations

United States
- New York
  - New York, New York, United States, 10021
    - Recruiting
    - Rockefeller University Hospital
    - Contact:
      
      Recruitment Specialist
      
      Phone Number: 800-782-2737
      
      Email: rucares@rockefeller.edu
    - Principal Investigator:
      
      Barry Coller, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Child
Adult
Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

For normal volunteers, we recruit from laboratory personnel and other volunteers from the NYC area. Patients with platelet disorders, coagulation disorders, or white blood cell disorders, are recruited from among patients referred by other physicians to the P.I. for assessment or via the internet.

Description

Inclusion Criteria:

A. Normal Healthy Volunteers:

Normal healthy volunteers
18 years of age or older
Either sex
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
Either sex
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.

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Observational Models: Case-Control
Time Perspectives: Prospective

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Normal Normal, healthy volunteers 18 years of age or older of either sex and any ethnic background
Glanzmann thrombasthenia Patients with Glanzmann thrombasthenia or their relatives, inherited qualitative and/or quantitative platelet disorders, inherited disorders of white blood cells, inherited disorders of coagulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Rockefeller University

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

Principal Investigator: Barry Coller, MD, Rockefeller University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Link to clinical study description

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2005

Primary Completion (Estimated)

June 1, 2030

Study Completion (Estimated)

June 1, 2030

Study Registration Dates

First Submitted

September 28, 2005

First Submitted That Met QC Criteria