Official Title
Pharmacogenomics of Warfarin in Hispanics and Latinos
Brief Title
Pharmacogenomics of Warfarin in Hispanics and Latinos
Protocol ID
NCT02972385
Lead Sponsor
University of Arizona
Brief Summary
Warfarin is a commonly used blood thinner to treat and prevent blood clots. It is
important to take the right dose of warfarin because too much can increase the risk of
bleeding and too little can increase the risk of blood clots. This is why patients are
closely monitored especially when they begin warfarin therapy. When clinicians prescribe
warfarin, they have to consider different factors such as patient's age, body size, diet,
and other medications that can interact with warfarin.
Certain genes have also been found to affect warfarin dose. Individuals have variations
in these genes, which can help explain why some patients need higher dose and others
require less. These factors have been used to better predict a patient's warfarin dose
requirement. However, these predictions were created based on Caucasian populations and
they may not be accurate in predicting a safe warfarin dose if a patient is not
Caucasian. This study aims to identify new genetic variation that affects warfarin dosing
in Hispanic and Latino populations and try to better predict a Hispanic or Latino
patient's warfarin dose requirement.
Detailed Description
If the patient is willing to hear about the study, during routine clinical care, one of
the patient's providers will approach patients meeting the study criteria about
participation in the study. Study personnel will not approach potential participants
unless permission is given to the patient's provider. If the patient would like to
participate in the study, study personnel will discuss details of the study in person
during the patient's routine clinical care visit. There will also be a flyers available
for posting and for distribution to potential participants.
Participants consenting to the study will be asked to provide a cheek swab or mouthwash
sample to provide buccal cells for DNA extraction. If the patient is receiving a blood
draw during their regular clinical appointment, participants will be asked for a blood
sample of 15 milliliters. Genomic DNA will be isolated for genotyping and patient plasma
samples will also be stored.
Linear regression will be used to test association of SNPs with therapeutic warfarin dose
using the algorithms derived by the International Warfarin Pharmacogenomics Consortium.
The primary phenotype (weekly stable warfarin dose) will be transformed by square root.
SNPs and other variables associated with warfarin dose will be assessed in univariate
analyses and entered into stepwise linear regression to determine the adjusted
association with dose requirements using R2. Quality control procedures will include
deviation from Hardy-Weinberg Equilibrium, and SNP and sample exclusions based on call
rates. Ancestry-informative marker (AIM) analysis will be performed to estimate ancestry
in each individual.
Enrollment Count
400 participants
Eligibility Criteria
Inclusion Criteria:
- At least 18 years of age
- Ability to give informed consent
- Therapeutic INR for at least 2 consecutive clinic visits
- Self-identifies as Hispanic or Latino
Exclusion Criteria:
- Less than 18 years old
- Unable to give informed consent
- Severe hepatic impairment
Filters
Thrombosis
Hemorrhage
RECRUITING
ADULT
OLDER_ADULT