nephropathy in those countries. Genetics Though various associations have been described, no consistent pattern pointing to a single susceptible gene has been identified to date. Associations described include those with C4 null allele, factor B Bf alleles, MHC antigens and IgA isotypes. ACE gene polymorphism (D allele) is associated with progression of kidney failure, similar to its association with other causes of chronic kidney failure. However, more than 90% of cases of IgA nephropathy are sporadic, with a few large pedigrees described from Kentucky and Italy (). History William Heberden, the elder, first described the disease in 1801 in a 5-year-old child with abdominal pain, hematuria, hematochezia, and purpura of the legs. In 1837, Johann Lukas Schönlein described a syndrome of purpura associated with joint pain and urinary precipitates in children. Eduard Heinrich Henoch, a student of Schönlein's, further associated abdominal pain and renal involvement with the syndrome. In 1968, Jean Berger (1930–2011), a pioneering French nephrologist, with co-author, the electron microscopist Nicole Hinglais, was the first to describe IgA deposition in this form of glomerulonephritis and therefore it is sometimes called Berger's disease. References External links IGA Nephropathy on National Institute of Diabetes and Digestive and Kidney Diseases Kidney diseases Autoimmune diseases