OTP and obesity due to melanocortin 4 receptor deficiency: We next investigated the potential role of OTP in humans by analyzing exome sequencing and targeted resequencing data on 2548 European ancestry individuals with severe, early-onset obesity recruited to the Genetics Of Obesity Study (GOOS; mean body mass index [BMI] standard deviation score 3; age of onset <10 years) and 1,117 ancestry-matched controls (Methods) [21].