This study aimed to investigate the roles of eight genetic loci—PNPLA3-Ile148Met, PNPLA3-Lys434Glu, GCKR-Leu446Pro, TM6SF2-Glu167Lys, LEPR-Lys109Arg, LEPR-Lys656Asn, IRS1-Gly971Arg, and KLB-Arg728Gln—in the susceptibility to MASLD in Chinese children and adolescents, in order to provide scientific evidence for genetic research on MASLD. The gene discussed is IRS1; the disease is metabolic dysfunction-associated steatotic liver disease.