Pediatric Rheumatology Online Journal →
June 2003 → Epidemiology, Classification, Immunology and Immunogenetics →
Abstract #5
LINKING CLINICAL AND GENEALOGIAL DATABASES TO IDENTIFY EXTENDED MULTIPLEX PEDIGREES WITH JUVENILE IDIOPATHIC ARTHRITIS
S. Prahalad,1 E. O'Brien,2 A. Fraser,2 R. Kerber,2,3 G. Mineau,2,3 J. Bohnsack.1
1Pediatrics, U of Utah SOM, Salt Lake City, UT, United States; 2Huntsman Cancer Institute, U of Utah, Salt Lake City, UT; 3Dept of Oncological Sciences, U of Utah, Salt Lake City, UT
Objectives: While juvenile idiopathic arthritis (JIA)-affected sibpairs exist, extended multiplex pedigrees are rare. We aimed to identify JIA-clusters by linking a clinical database with a genealogical database.
Methods: Information on ~700 cases with JIA or possible JIA was entered into a clinical database. The Utah Population Database (UPDB) is a computerized genealogy database of ~6 million records. A program called Integrity was used to perform probabilistic linking of records in these 2 databases. Weights are calculated to measure the contribution of each field to the probability of matching 2 records. A link is accepted if the composite weight is above a specified threshold. After establishing links between cases and matched family records, pairwise combinations of cases are assessed to determine if they share common ancestors (CA). If a CA is found, the kinship coefficient is calculated to find the degree of relatedness. From a list of CA, extended families with case-clusters are identified.
Results: In all, 443 (63.6%) cases linked to the UPDB. The 4 largest clusters had 5 cases each. Cluster 1 had 2 patients with oligoJIA, and 1 each with poly RF-ve, poly RF+ve, and probable systemic JIA. Cases were 8th to 12th-degree relatives. Cluster 2 had 5 cases, all with oligoJIA. There was a sibpair, and 7th to 12th-degree relatives. Onset ages were 1.5, 1.5, 1.6, 2.5 and 15 years. Cluster 3 had 1 systemic, 1 poly RF-ve, 2 oligo and 1 IBD-related arthritis. Cases were 2nd to 12th-degree relatives. Cluster 4 had 3 poly RF-ve, 1 oligo and 1 systemic JIA. There was a sibpair and 7th to 9th-degree relatives.
Conclusions: Combining clinical and genealogical databases is a novel and powerful method to identify extended pedigrees of JIA. Though clusters are small and consist of distant relatives, examining patients within clusters and ascertaining previously undiagnosed relatives will be helpful for future genetic studies.