The role of some genetic polymorphisms of biotransformation enzymes [NQO1, CYP1A1, CYP2D6, CYP3A4/5, NAT1/2, glutathione-S-transferase (GST) GSTT1, GSTM1, GSTP1 and GSTA1] has already been examined in BEN/AAN patients (Atanasova et al. 2005; Chen et al. 2012a; He et al. 2005; Reljic et al. 2014; Stefanovic et al. 2006; Toncheva et al. 1998, 2004; Toncheva 2006; Wang et al. 2009). Here, NAT1 is linked to Balkan nephropathy.