While studies have shown that plasma composition with respect to serum albumin and hematocrit are largely unaffected by obesity, it changes with respect to α1-acid glycoprotein (AAG), which increases approximately 2-fold with obesity in adults (Benedek et al., 1983, 1984; Blouin et al., 1987; Gerhart et al., 2021). The gene discussed is MPG; the disease is obesity due to melanocortin 4 receptor deficiency.