Several reports during the last 3 decades demonstrated de novo deletions (Tarleton et al., 1993; Gu et al., 1994; Petek et al., 1999; Luo et al., 2014; Zink et al., 2014; Jorge et al., 2018; Myers et al., 2019) spanning the FMR1 or both the FMR1 and FMR2 gene (Clarke et al., 1992; Wolff et al., 1997; Fengler et al., 2002; Probst et al., 2007), resulting in the loss of FMRP and a range of phenotypes including physical, cognitive and behavioral features, intellectual disabilities (ID), seizures, and obesity, similarly observed in individuals with FXS (Coffee et al., 2008). Here, FMR1 is linked to obesity due to melanocortin 4 receptor deficiency.