DHFR 19 bp Deletion Polymorphism and Folic Acid Utilization

October 23, 2017 updated by: Tufts University
A genetic variation in the gene for the protein dihydrofolate reductase (DHFR) that is necessary to utilize folic acid (a synthetic form of the B vitamin folate found in supplements and fortified food), increases the risk for breast cancer in multivitamin users and, when present in mothers who used folic acid supplements during pregnancy, increases the risk for cancer of the eye of their children. The aim of the proposed research is to understand how a common genetic variation in the gene for DHFR affects the function of this protein and the ability of the body to use folic acid.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

A 19bp deletion polymorphism of intron 1 of dihydrofolate reductase (DHFR 19bpdel) increases the risk for breast cancer, and retinoblastoma of the offspring, in folic acid supplement users. Folic acid is a synthetic form of folate present in fortified foods and supplements that must be converted to tetrahydrofolate by DHFR to enter the metabolism. Individuals homozygous for DHFR 19bpdel have higher prevalence of unmetabolized folic acid in plasma and lower incorporation of folic acid into tissues. How the DHFR19bpdel (17% homozygosity in US) affects DHFR activity and folate metabolism to increase cancer risk is not understood. Studies on this topic are urgent in the light of mandatory folic acid fortification in the US and other countries. The objective of this project is to characterize the effect of DHFR 19bpdel on DHFR activity and folate pathway reactions and to determine if the effect of DHFR 19bpdel can be alleviated with folinic acid, which is a folate source that need not be converted by DHFR. The specific aims of this project are to 1] Determine expression of DHFR mRNA and protein, splicing of intron 1 and enzyme activity in white blood cells from 3 DHFR genotypes. 2] Determine the effect of DHFR 19bpdel and folic acid or folinic acid concentration on cell growth, and folate pathway reactions in white blood cells in homozygotes for DHFR 19bpdel and those who lack the polymorphism. Results of this study will guide measures to reduce this modifiable cancer risk associated with DHFR 19bpdel.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
117

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

21 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Probability Sample

Study Population

Healthy pre-menopausal females aged 21-45 from Metro Boston area

Description

Inclusion Criteria:

  • Adult premenopausal women aged 21-45 in general good health, non-pregnant, minimum weight of 110 pounds.

Exclusion Criteria:

  • Smoking, a terminal illness, any known chronic illness, rheumatoid arthritis, heart, kidney, liver or gastrointestinal disease requiring treatment, antifolate medications, metformin use.
  • More than 2 drinks a day.
  • Pregnant women have different metabolism when compared to other adults hence they will not be included in the study.
  • Non-English speaking subjects will be excluded since the study involves a computer based diet history questionnaire in English. The budget for this project does not include the cost of an interpreter.

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: Ecologic or Community
  • Time Perspectives: Cross-Sectional

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
DHFR mRNA and protein abundance
Time Frame: 1 year
DHFR mRNA and protein abundance determined for the 19 bp deletion genotypes
1 year

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Reactions of folate pathway
Time Frame: 1 year
Effect of DHFR 19bp deletion on reactions of folate pathway determined in cell culture conditions
1 year

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tufts University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ligi Paul, Ph.D., Tufts University

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

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2013

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2015

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2015

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 20, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 23, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 24, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 24, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 23, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2017

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ORA# 1211023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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