PRG4 and camptodactyly-arthropathy-coxa vara-pericarditis syndrome: Whole-exome sequencing was performed in both patients, which showed the existence of (to the best of our knowledge) a novel pathogenic (NM_005807.6):c.3445A > T(p.Lys1149Ter) homozygous mutation in the PRG4 gene associated with CACP syndrome.