Other AAM genes have recognized roles in sex hormone secretion and gametogenesis (ACVR2A, CYP19A1, HSD17B7, INHBA, INHBB, MC3R and PCSK2)42, are disrupted in rare monogenic disorders of multiple pituitary hormone deficiency (OTX2, SOX2, SOX3 and SST)43, monogenic obesity (BDNF, LEPR, MC4R, NTRK2, PCSK1 and SH2B1)44 or syndromes characterized by hypogonadism (Noonan syndrome: BRAF and SOS1; Bardet–Biedl syndrome: BBS4; Prader–Willi/Angelman syndrome: NDN, SNRPN and UBE3A)45–48. Here, NDN is linked to obesity due to melanocortin 4 receptor deficiency.