Sarcoid Genetic Analysis (SAGA)

BACKGROUND:

Sarcoidosis is a rare systemic granulomatous disease that mainly affects young to middle aged adults, and more severely affects African Americans than Caucasians. The etiology of sarcoidosis is not yet known, and epidemiological studies have only identified general risk factors including age, sex, race, and family history. Sarcoidosis may also be influenced by environmental factors, although the particular environmental agents have not yet been clearly defined. While previous studies have provided evidence for familial clustering, little is known about the genes that influence predisposition to sarcoidosis.

DESIGN NARRATIVE:

This is a multicenter consortium genetic epidemiology study. The investigators will accomplish their goal by organizing a 10-site multi-center consortium to recruit an adequate sample of sarcoidosis families for analysis. They plan to use the affected sibling pair linkage analysis to scan the genome for linked chromosomal regions, transmission disequilibrium testing to evaluate candidate genes in those regions with evidence for linkage, and an environmental questionnaire to collect data to test for possible interactions of susceptibility genes with exogenous risk factors. Genotyping and analysis of data are scheduled to begin in July, 2001 with completion of all analysis by April, 2004.

The study consists of a Clinical Core, a Data Coordinating Core, and a Genetics Core with a DNA Processing Center and a Genotyping Center. Eight of the ten clinical centers comprising the Clinical Core are members of the ACCESS, A Case Control Etiology of Sarcoidosis Study.