The biosynthetic activities of protein and collagen from the patient of kinky hair disease, were reduced to 70 and 50%, respectively, compared with control.In tissue cultures, fast-green FCF staining coarse granules were found in the cytoplasm of skin fibroblasts from the patient.Ultrastructurally, collagen fibrils by iliac cartilage biopsy were irregular in width. Ruthenium red staining granules, presumed to be proteoglycans in the cartilage matrix, were relatively small in size and few in number. Chondrocytes showed poor development of organelles and relatively small glycogen accumulation.SpeculationThe metabolic disorder of copper may play a role in the reduced biosynthetic of collagen. There is a possibility that fast-green FCF staining coarse granules in the cytoplasm of skin fibroblast, may be a precursor material of collagen. The appearance of huge collagen fibrils in the cartilage matrix may be related to the decreased number of proteoglycan granules which are considered to play a role in fiber formation.