Mutations in SLC3A1 and SLC7A9 cause cystinuria (Calonge et al. 1995; Palacin 1994; Miyamoto et al. 1995; Bisceglia et al. 2001; Egoshi et al. 2000; Font et al. 2001; Dello Strologo et al. 2002). The gene discussed is SLC7A9; the disease is cystinuria.