About 118 candidate genes are so far associated with obesity.[9] Some of the important candidate genes involved in causing obesity are the genes encoding leptin (LEP), leptin receptor (LEPR), melanocortin 4 receptor (MC4R), adiponectin (ADIPOQ), corticotrophin releasing hormone1 (CRHR1), prohormone convertase1 (PC1), pro-opiomelanocortin (POMC), and resistin (RETN).[10] Among them, leptin and its receptor play the central role. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.