Trial record 2 of 13 for:    Thalassemias | Recruiting, Not yet recruiting, Available Studies | NIH, U.S. Fed

Screening for Alpha Thalassemia in Healthy Volunteers

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02692872
Recruitment Status : Recruiting
First Posted : February 26, 2016
Last Update Posted : January 15, 2019
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Allergy and Infectious Diseases (NIAID) )

February 25, 2016
February 26, 2016
January 15, 2019
May 8, 2017
December 31, 2023   (Final data collection date for primary outcome measure)
Identify Presence of Double Alpha Globin Deletions in Healthy Volunteers. [ Time Frame: Ongoing ]
As this is not a treatment protocol, there is no primary endpoint. The primary objective is to identify presence of double alpha globin deletions in healthy volunteers.
Identify Presence of Double Alpha Globin Deletions in Healthy Volunteers. [ Time Frame: Ongoing ]
Complete list of historical versions of study NCT02692872 on Archive Site
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Screening for Alpha Thalassemia in Healthy Volunteers
Screening for Alpha Globin Deletions


Alpha thalassemia is a blood disorder. It is caused by genetic deletions. Part of the DNA is missing from a group of genes called alpha globin. Alpha thalassemias are some of the most common genetic deletions. We are testing for alpha thalassemia trait. Alpha thalassemia trait is when someone has only two out of the normal four alpha globin genes. In some people, they lead to no symptoms. Others have changes that lead to disease, including mild anemia. Researchers want to learn more about alpha thalassemia and blood vessels. This may allow them to develop new treatments for blood diseases such as sickle cell disease.


To better understand how alpha globin deletions in healthy people affect blood vessels.


Healthy volunteers ages 18 50 who self-report African ancestry.


Participants will provide a one-time saliva sample. This can be by mail, in-person at a study event, or at NIH.

Participants will get a small kit to collect their saliva sample. The kit has easy instructions. The sample does not need to be put in the refrigerator.

Participants will spit a small amount of saliva (less than half a teaspoon) into a collection tube.

Participants will close the funnel lid tightly, and then unscrew the funnel lid from the tube. They will then close the tube tightly with the small cap provided and shake the tube for 5 seconds.

Participants will place the tube in the provided envelope and mail it to NIH. The specimen will be stored and processed in the lab.

Participants may be invited to participate in more research studies, whether or not researchers find that they have alpha thalassemia trait.

Many of the complications of sickle cell disease, such as stroke, kidney damage, skin ulceration,pulmonary hypertension, and cardiac hypertrophy are prevented, delayed or reduced by inheritance of one of more deletions of the alpha globin genes. Our long-term research goal is to understand how deletions of alpha globin protect against the vascular complications of sickle cell disease.

Deletions of alpha globin are common and found in approximately 5% of the world s population.They are especially common among Africans and people of African ancestry, as well as in India, China, and the Pacific Islands, where prevalence can range from 5 - 80%. A single deletion has little effect on the red blood cell, but two deletions can give rise to alpha thalassemia, a mild microcytic anemia. Patients with sickle cell disease who have two alpha globin deletions tend to have a higher hemoglobin level, smaller red blood cells, and a lower fraction of circulating reticulocytes consistent with decreased hemolysis and red cell turnover. They also have a lower number of dense or irreversibly sickled cells. These changes might explain why alpha globin deletions reduce the severity of sickle cell disease.

However, a novel function for alpha globin as a regulator of endothelial nitric oxide (NO) has recently been identified that raises new questions about how alpha globin deletions protect against sickle cell disease. We hypothesize that individuals with two alpha globin deletions will have decreased gene expression and protein levels of alpha globin in vascular endothelium, permitting more NO to diffuse across the myoendothelial junction, compared to individuals who have all four alpha globin genes intact. In this protocol we will screen healthy volunteers to identify those with two alpha globin deletions; these individuals as well as matched controls will be referred to a separate protocol to undergo studies of vascular endothelial function.

Observational Model: Other
Time Perspective: Other
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Non-Probability Sample
All subjects ages 18-50 will be considered for the protocol. We have excluded anyone older than age 50 in order to avoid confounders of older age and cardiovascular disease in asymptomatic subjects. No subject will be excluded from participation based on gender. Subjects will be enrolled based on selfreport of African ancestry given the higher prevalence of the genetic mutation in these populations.
Alpha Thalassemia
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Aged 18-50

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
December 31, 2023
December 31, 2023   (Final data collection date for primary outcome measure)

Subject report of the following:

  1. Age 18 - 50
  2. Self-report of African ancestry
  3. Willingness and legal ability to give and sign informed study consent


There are no exclusion criteria for this screening protocol

Sexes Eligible for Study: All
18 Years to 50 Years   (Adult)
Contact: Mary J Jackson, R.N. (240) 292-4690
United States
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National Institutes of Health Clinical Center (CC) ( National Institute of Allergy and Infectious Diseases (NIAID) )
National Institute of Allergy and Infectious Diseases (NIAID)
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Principal Investigator: Amy P Ruhl, M.D. National Heart, Lung, and Blood Institute (NHLBI)
National Institutes of Health Clinical Center (CC)
January 11, 2019