Cardiometabolic Risk Markers in Children With Obesity and Variants in MC4R Pathway-related Genes

Context: Variants in melanocortin 4 receptor (MC4R) pathway-related genes have been associated with obesity. The association of these variants with cardiometabolic parameters are not fully known. Objective: We compared the severity of obesity and cardiometabolic risk markers in children with MC4R pathway-related clinically reported genetic variants relative to children without these variants. Methods: A retrospective chart review was performed in children with obesity who underwent multigene panel testing for monogenic obesity. Results: Data on a total of 104 children were examined, with 93 (89%) identified as White. Thirty-nine (37.5%) patients had clinically reported variants in the MC4R pathway, and the remaining 65 patients did not have reported MC4R pathway-related variants. Among the MC4R-related variants, PCSK1 risk alleles were most common, reported in 15 children (14%). The maximum body mass index percent of the 95th percentile was not different between groups (P =. 116). Low-density lipoprotein cholesterol (LDL-C) was not different between groups (P =. 132). However, subgroup analysis demonstrated higher LDL cholesterol in children with the PCSK1 c.661A>G risk allele relative to those with MC4R-related variant of uncertain significance (P =. 047), negative genetic testing (P =. 012), and those with non-MC4R related variants (P =. 048). The blood pressure, fasting glucose, hemoglobin A1C, total cholesterol, alanine transaminase, and high-density lipoprotein cholesterol were not different between groups. Conclusion: Variants in the MC4R pathway-related genes were not associated with severity of obesity and cardiometabolic risk markers except for the c.661A>G PCSK1 risk allele, which was associated with higher LDL-C levels.