Familial cases of Berger's disease and anaphylactoid purpura.

To the Editor: Davin, Berge and Weening recently published a review pointing out the similarities and the differences between IgA nephropathy (IgAN) and Henoch-Schönlein purpura (HSP) nephritis1. They reported that IgAN and HSP could "be related diseases since both may be encountered consecutively in the same patient, have been described in identical twins and bear identical pathological and biological abnormalities." We would like to report on the results of the collaborative study of the Society of Nephrology (France) carried out in the late 1980s2,3. This survey revealed 40 families with two or three members having biopsy-confirmed IgAN. In five of these 40 families, one or two additional relatives presented with HSP, with or without renal involvement: a father and son with IgAN, and a second son with HSP; a father and two sons with IgAN, and a third son's daughter with HSP; an uncle and nephew with IgAN, and an uncle's sister with HSP; two sisters with HSP, and a brother and a nephew with IgAN; and an uncle and niece with IgAN, and a nephew with HSP. In addition, there were 18 other families in which one member only had IgAN and one (or two relatives) had HSP. In our opinion, the possibility of such familial cases of IgAN and HSP can also be considered as another link between the two diseases.