Ignite Creation Date:
2024-05-06 @ 8:13 AM
Last Modification Date:
2024-10-26 @ 11:57 AM
Study NCT ID:
NCT02692872
Status:
ACTIVE_NOT_RECRUITING
Last Update Posted:
2024-06-28
First Post:
2016-02-25
Brief Title:
Screening for Alpha Thalassemia in Healthy Volunteers
Sponsor:
National Institute of Allergy and Infectious Diseases NIAID
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Screening for Alpha Globin Deletions
Status:
ACTIVE_NOT_RECRUITING
Status Verified Date:
2024-10-01
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Background
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
Objective
To better understand how alpha globin deletions in healthy people affect blood vessels
Eligibility
Healthy volunteers ages 18-39 who self-report African ancestry
Design
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
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
Objective
To better understand how alpha globin deletions in healthy people affect blood vessels
Eligibility
Healthy volunteers ages 18-39 who self-report African ancestry
Design
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
Detailed Description:
Many of the complications of sickle cell disease such as stroke kidney damage skin ulcerationpulmonary 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 populationThey 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
Deletions of alpha globin are common and found in approximately 5 of the world s populationThey 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
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 16-I-0065 | None | None | None |