Given the combination of camptodactyly, non- inflammatory arthropathy and previous pericarditis a diagnosis of Camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP) was considered and targeted exome sequencing revealed a homozygous PRG4 pathogenic variant (c.3462_3465delGACT p.Thr1155LeufsTer7) (Table 1). The gene discussed is PRG4; the disease is camptodactyly-arthropathy-coxa vara-pericarditis syndrome.