Chondroitin sulfate, a monomer of the polysaccharide portion of proteoglycan, has been shown to reduce the symptoms of osteoarthritis, possibly by increasing the synthesis of the extracellular matrix. Achondroplasia: Reduced proliferation of chondrocytes in the epiphyseal plate of long bones during infancy and childhood, resulting in dwarfism. Costochondritis: Inflammation of cartilage in the ribs, causing chest pain.