AZGP1 and obesity due to melanocortin 4 receptor deficiency: In addition, our study found a negative relationship between ZAG mRNA levels and obesity-related parameters including body weight, waist circumference and BMI, which was consistent with reports by Mracek et al. and by Selva et al. in a Caucasian population (Selva et al., 2009; Mracek et al., 2010).