Familial occurrence frequencies and relative risks for systemic sclerosis (scleroderma) in three United States cohorts

Arthritis Rheum. 2001 Jun;44(6):1359-62. doi: 10.1002/1529-0131(200106)44:6<1359::AID-ART228>3.0.CO;2-S.


Objective: To determine the frequency with which scleroderma (systemic sclerosis; SSc) recurs in families and the familial relative risk (lambda) in the US.

Methods: Family histories of SSc were prospectively surveyed in 3 large US cohorts of SSc patients, 2 in Texas and 1 in Michigan. Diagnoses of familial SSc were verified by rheumatologist evaluation and/or review of medical records. Familial relative risks for first-degree relatives (lambda1) and siblings (lambdas) were calculated using actual reported counts of first-degree relatives in 2 cohorts and recent estimates of SSc prevalence in the US.

Results: Compared with the estimated prevalence of SSc in the US (2.6 cases/10,000 population [0.026%]), the disease occurred in 1 or more first-degree relatives in 1.5-1.7% of SSc families in the 3 cohorts (or 11 of 703 families [1.6%]), a significant increase. Familial relative risks in first-degree relatives in the 3 cohorts ranged from 10 to 16 (13 combined), and in siblings they ranged from 10 to 27 (15 combined).

Conclusion: SSc occurs significantly more frequently in families with scleroderma (1.6%) than in the general population (0.026%). A positive family history of SSc is the strongest risk factor yet identified for SSc; however, the absolute risk for each family member remains quite low (<1%).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blacks / genetics
  • Cohort Studies
  • Family Health
  • Female
  • Genetic Predisposition to Disease*
  • Hispanic or Latino / genetics
  • Humans
  • Male
  • Michigan / epidemiology
  • Middle Aged
  • Nuclear Family
  • Risk
  • Scleroderma, Systemic / ethnology
  • Scleroderma, Systemic / genetics*
  • Texas / epidemiology
  • Whites / genetics