CD79A and hereditary spastic paraplegia: It is worth noting that the IgA-type antibodies associated with pathogenesis in the peripheral circulation of patients with nephritis-type HSP or IgA nephritis are mainly in the form of multimers [6,7], and the cells secreting the corresponding IgA-type antibodies are present in the bone marrow, tonsils and lymphatic follicles in the intestinal mucosa, along with the increase in number [8,9].