IGHA1 and hereditary spastic paraplegia: It was shown, that among the two known subclasses of IgA antibodies, vascular inflammation in HSP is caused by IgA1 with abnormal O-glycosylation in the hinge region, which under various stimuli (infections, drugs, vaccinations, etc.)form C3 containing immune complexes (also containing IgG, IgM, C1q) that are deposited in the vessels and in patients with nephropathy - in the glomeruli [1, 3, 5, 6].