(a) (CLDN19):c.241C>T, p.R81W (MIM#610036), hypomagnesemia 5, renal, with ocular involvement (MIM#248190, AR), homozygous.(b) COL1A1:c.1249C>G, p. P417A (MIM#120150), osteogenesis imperfecta, type I (MIM#166200, AD), heterozygous. The gene discussed is CLDN19; the disease is osteogenesis imperfecta.