In gender-based analysis, irisin levels did not differ between males and females in PWS (22.08 ± 0.8 and 23.07 ± 1.1 ng/ml, p =0.5) and controls (27.1 ± 2.4 and 24.0 ± 1.4 ng/ml p=0.07). Here, FNDC5 is linked to Prader-Willi syndrome.