OBJECTIVES: I. Determine whether defects in fibrillin-1 cellular processing are present in
the tsk1 mouse model that carries a known FBN1 gene rearrangement and in a population of
Choctaw Native American patients with systemic sclerosis who have a strong genetic
predisposition to the disease.
II. Determine the ultrastructural features of fibrillin-1 in these patients. III. Screen
the FBN1 gene for mutations beginning at the regions homologous to the tsk1 duplication and
latent transforming growth factor binding proteins in these patients and in an unaffected
Choctaw control group.
IV. Determine the correlation between fibrillin-1 abnormalities and clinical presentation,
autoantibodies, and ethnicity.
Patients undergo punch skin biopsy obtained from the upper arm or back. Studies of
fibrillin-1 synthesis and cellular processing, and FBN1 mutational analysis, linkage
analysis, and genetic mapping are performed on the tissue samples. Patients from all major
US ethnic groups (Caucasian, Hispanic, African Americans) will be recruited for the study in
the next 2 years.
PROTOCOL ENTRY CRITERIA:
Diagnosis of systemic sclerosis in accordance with the American College of Rheumatology
Positive for systemic sclerosis antibodies (e.g., anticentromere, antitopo,
antifibrillarin, or antiRNA polymerase)