Letter to the editor: About the characterization of the genetic variantsF2 and G1 of cow’s milk κ-casein

Farrell et al. (2004) reported that both k-casein genetic variants F2 and G1 of cow’s milk arise from a single mutation of k-CN B, whereas in the original paper of Prinzenberg et al. (1996), it was reported that both variants arise from a single mutations of k-CN A: a His (F2) residue for Arg (A) at position 10 and a Cys (G1) residue for Arg (A) at position 97. This is also documented in Formaggioni et al. (1999), Prinzenberg et al. (2008), and Caroli et al. (2009). The latter 2 papers reported a further mutation in G1: an Ile (G1) residue for Thr (A) at position 135.