WHAT IS CACP SYNDROME?

CACP (Camptodactyly-Arthropathy-Coxa Vara-Pericarditis) represents a number of symptoms that are caused by a mutation in the Proteoglycan4 (PRG4). This mutation causes dysfunction in the protein lubricin, which is responsible for lubrication in body cavities such as the joints and around the heart and lungs. Currently, the most well described symptoms are:

Camptodactly- Permanent bending and/or drifting of fingers and/or toes. 

Arthropathy- A disorder of the joints associated with swelling and inflammation as seen in many forms of arthritis.

Coxa Vara- A hip disorder in which there is a reduced angle between the femoral neck and its shaft. This can result in a leg discrepancy and limp.

Pericarditis- An inflammation of the tissue surrounding the heart.

While these are the most well known symptoms, there are more anecdotal or potential symptoms that are unknown because CACP is largely unstudied.  This also means that the true incidence of CACP is currently a best estimate. CACP syndrome was first described in 1999 By Dr. Matthew Warman representing the first study to associate the PRG4 mutation with the symptoms listed above.  Since then his efforts have focused on characterizing and utilizing an animal model to examine the pathology of CACP. However, other research has been largely limited to highlighting the fact that CACP is commonly misdiagnosed as Juvenile Arthritis. This fact not only shows unfortunate it is that these misdiagnoses still occur, but also bring to light that much more information is needed on this rare genetic condition.