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

November 6, 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

Completed

Conditions

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

Observational

Enrollment (Actual)

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 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

Ages Eligible for Study

1 month to 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Genders Eligible for Study

All

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

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
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

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

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

National Cancer Institute (NCI)

Investigators

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

<p>NIH Clinical Center Detailed Web Page</p>

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)

May 10, 1999

Study Registration Dates

First Submitted

November 3, 1999

First Submitted That Met QC Criteria

November 3, 1999

First Posted (Estimated)

November 4, 1999

Study Record Updates

Last Update Posted (Actual)

November 9, 2026

Last Update Submitted That Met QC Criteria

November 6, 2026

Last Verified

April 20, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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

Studies a U.S. FDA-regulated device product

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