DOCK2 and progressive pseudorheumatoid arthropathy of childhood: In conclusion, the present study highlighted the number of deliveries and the number of family members living together as two critical confounding factors in elucidating the genetic underpinnings of PPD and identified significant associations between PPD and eight loci at DAB1, UGT8, DOCK2, ZNF572, DIRAS2, ZNF618, PTPRM, and PDGFB.