Anorexia nervosa (AN) is a severe debilitating eating disorder. To date, only very few genes that predispose to AN have been identified. An alternative to association studies is to characterize ultra-rare variants in familial forms of AN. Here, we have implemented this approach to identify pathways that contribute to the development of AN through the analysis of a family with three members suffering from AN by exome analysis. We identified three ultra-rare deleterious variants in three genes (DRD4, CCKAR, NMS), already connected to the reward pathway, that co-segregate with AN, suggesting that this pathway might be playing a predisposing role in AN at least in familial forms.