Examination of Clinical and Laboratory Abnormalities in Patients With Defective DNA Repair: Xeroderma Pigmentosum, Cockayne Syndrome, or Trichothiodystrophy

September 15, 2026 updated by: National Cancer Institute (NCI)
Four rare genetic diseases, xeroderma pigmentosum (XP), Cockayne syndrome (CS), the XP/CS complex and trichothiodystrophy (TTD) have defective DNA excision repair although only XP has increased cancer susceptibility. We plan to perform careful clinical examination of selected patients with XP, XP/CS, CS, or TTD and follow their clinical course. We will obtain tissue (skin, blood, hair, buccal swabs) for laboratory examination of DNA repair and for genetic analysis. We hope to be able to correlate these laboratory abnormalities with the clinical features to better understand the mechanism of cancer prevention by DNA repair. Patients will be offered counseling and education for cancer control....

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

Three rare genetic diseases, xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD) have defective DNA excision repair although only XP has increased cancer susceptibility. We plan to perform careful clinical examination of selected patients with XP, CS, TTD, or overlap syndromes to follow their clinical course. We will obtain tissue (skin, blood, hair, or buccal cells) for laboratory examination of DNA repair and for histologic, protein, biochemical, and genetic analysis. We hope to be able to correlate these laboratory abnormalities with the clinical features to better understand the mechanism of cancer prevention by DNA repair. Patients will be offered counseling and education for cancer control.

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.
709

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

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Deborah E Tamura, R.N.
  • Phone Number: (240) 760-7355
  • Email: dt220a@nih.gov

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center

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

1 month and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients will be sought by contacting professional organizations (such as the American Academy of Dermatology-XP Task Force), lay support groups (such as the XP Society and the Share and Care CS Support Network) or by direct referral. Healthy volunteers or NIH staff will be recruited through the Program for Healthy Volunteers (CRVP@mail.cc.nih.gov), through the Patient Recruitment and Public Liaison Office (prpl@mail.cc.nih.gov), or as a self-referral through the clinicaltrials.gov web site (http://clinicaltrials.gov). Healthy volunteers may also be approached by a member of the LCBG, NCI regarding interest in participating on this protocol.

Description

  • INCLUSION CRITERIA:

  • Subjects age 6 weeks and above:

    • with clinical and/or laboratory documentation of typical features or suggestive clinical features of XP, CS, TTD, or overlap syndromes or
    • that are first degree relatives or other family members of participants with XP, CS, TTD, or overlap syndromes
  • Healthy volunteers of age 1 year and above (including NIH employees) willing to donate blood, skin, buccal cells, or hair.
  • Patients or legally authorized representatives must provide informed consent.

EXCLUSION CRITERIA:

-Inability or unwillingness to provide tissue (skin, blood, buccal cells or hair) for laboratory studies.

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
1
Subjects with clinical and/or laboratory documentation of typical features or suggestiveclinical features of XP, CS, TTD, or overlap syndromes
2
Family members of patients with XP, CS, TTD, or overlap syndromes
3
Healthy volunteers

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
Identify patients with genetic diseases
Time Frame: Up to 3 days
Proportion of patients with three rare genetic diseases; xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD)and overlap syndromes
Up to 3 days

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
Diagnosis confirmation
Time Frame: up to 3 days
-To confirm suspected cases of XP, CS, TTD, XP/TTD or overlap syndrome patients by review of clinical records, by clinical examination and by laboratory testing -To document presence (or absence) of cancers (skin, eye, tongue, or internal) in XP, XP/CS, CS, TTD, XP/TTD and other overlap syndrome patients-To document atypical clinical features or unusual environmental exposures of patients with XP, XP/CS, CS, TTD, XP/TTD and otheroverlap syndromes
up to 3 days
Tissue collection
Time Frame: up to 3 days
obtain tissue (skin, blood, hair or buccal cells) from XP, CS, TTD, XP/TTD or overlap syndrome patients, their first-degree relatives and healthy volunteers for establishment of cell cultures and for examination of DNA repair and genetic analysis
up to 3 days
identify molecular defects
Time Frame: up to 3 days
identify molecular defects in the DNA repair or other genes in cells from patients with XP, CS, TTD, XP/TTD or overlap syndromes and toattempt to correlate the defects with the clinical features
up to 3 days
overall survival
Time Frame: yearly
follow the clinical course of selected patients with XP, CS, TTD, XP/TTD or overlap syndromes
yearly

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.
National Cancer Institute (NCI)

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: Michael R Sargen, M.D., National Cancer Institute (NCI)

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.

General Publications

Helpful Links

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 (Actual)

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.
May 10, 1999

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).
November 3, 1999

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.
November 3, 1999

First Posted (Estimated)

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.
November 4, 1999

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.
September 16, 2026

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.
September 15, 2026

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.
April 20, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • 990099
  • 99-C-0099

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD recorded in the medical record will be shared with intramural investigators upon request. @@@@@@In addition, all large scale genomic sequencing data will be shared with subscribers to dbGaP.

IPD Sharing Time Frame

-Clinical data available during the study and indefinitely.@@@@@@-Genomic data are available once genomic data are uploaded per protocol GDS plan for as long as database is active

IPD Sharing Access Criteria

-Clinical data will be made available and with the permission of the study PI.@@@@@@-Genomic data are made available via dbGaP through requests to the data custodians.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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