ALDH18A1 and obesity due to melanocortin 4 receptor deficiency: The co-analysis of KEGG pathways revealed that ten differential metabolites (Cysteine-S-sulfate, L-Homoserine, 4-Hydroxyproline, N2-succinyl-L-glutamic acid 5-semialdehyde, isocitrate, malic acid, 5-Hydroxyindoleacetic acid, kynurenic acid, N-Acetylserotonin, and 11-beta-Hydroxyandrosterone-3-glucuronide) and five DEGs (Gm5096, Inmt, Aoc1, Aldh18a1, and Cyp1a2) were enriched in four obesity-related pathways.