REN and obesity due to melanocortin 4 receptor deficiency: The action on kidneys appears to be directly through the effects also on renin-secreting cells of the juxta-glomerular apparatus, whose stimulation may lead to increased natriuresis and reduce hyperfiltration, and indirectly by the reduction of angiotensin II levels, the increase in nitric oxide with consequently endothelial vasodilation and the improvement of risk factors of kidney disease (hyperglycemia, hypertension, obesity) (20).