,31,32,33 It is noteworthy that there are also case reports of individuals with FXS exhibiting a Prader-Willi phenotype (i.e., hyperphagia and obesity), which was likely caused by reduced cytoplasmic FMRP interacting protein (CYFIP1) expression.108. Here, CYFIP1 is linked to obesity due to melanocortin 4 receptor deficiency.