The rs 396991 of CD16A has been associated with rheumatoid arthritis [21,22], systemic lupus erythematosus [23,24], vasculitis [26], demyelinating disease [27], immune thrombocytopenic purpura [28] and myasthenia gravis [29]. Here, FCGR3A is linked to autoimmune thrombocytopenic purpura.