WFS1 and type 2 diabetes mellitus: 1998; Strom et al. 1998). Nonautoimmune degeneration of pancreatic β‐cells is common for WS patients (Karasik et al. 1989). In patients with WS high levels of endoplasmic reticulum (ER) stress and pancreatic β‐cell death may be associated with impaired β‐cell function as in the case of type 2 diabetes (T2D) (Fonseca et al. 2005). Genetic studies have also shown a link between the risk of developing T2D and WFS1 (Minton et al. 2002; Sandhu et al. 2007; Florez et al. 2008; Franks et al. 2008; van Hoek et al. 2008; Cheurfa et al. 2011).