To the best of our knowledge, this is the first time MMP-9, MPO and MIF have been investigated in PWS, and our results of higher degree of inflammation, even after control for leptin, CRP, abdominal circumference, VAI and BMI, are in accordance with studies showing that systemic inflammation is higher even in comparison with equally obese persons [14, 23]. This evidence concerns the gene MMP9 and Prader-Willi syndrome.