El-Shanti et al. (1997) described a consanguineous Jordanian family with at least six members from two generations affected with progressive pseudorheumatoid arthropathy of childhood (PPAC). Homozygosity mapping using DNA pooling approach performed by El-Shanti et al. (1998) showed linkage in a 20 cM region on the long arm of chromosome 6. However, no mutations were identified on examining the COL10A1 gene present in this region as a candidate gene.

Hurvitz et al. (1999) used a positional candidate approach and identified WISP3 as the gene responsible for progressive pseudorheumatoid arthropathy of childhood (PPAC) in a set of PPAC patients, which included three unrelated Jordanians and two unrelated patients of Saudi Arabian origin.

Al-Awadi et al. (1984) reported an Arab family with multiple members affected with progressive pseudorheumatoid arthropathy of childhood (PPAC). Eight patients identified were all born to consanguineous parents, and were related through a common ancestor, indicating the autosomal recessive nature of the disease.

Bennani et al. (2007) reported a 4-year-old girl with progressive pseudorheumatoid dysplasia. Two similarly affected family members, a brother and a paternal uncle, were also identified and diagnosed with progressive pseudorheumatoid dysplasia during this study.