Accordingly, it has been indicated to have a close link between inborn errors or polymorphisms of TYK2 gene and a wide spectrum of autoimmune diseases, inflammatory diseases, tumors, and obesity (Strobl et al., 2011, Casanova et al., 2012, O'Shea et al., 2013, Derecka et al., 2012). This evidence concerns the gene TYK2 and obesity due to melanocortin 4 receptor deficiency.