ACTN3 and obesity due to melanocortin 4 receptor deficiency: In Khanal et al. [23], both ACTN3 rs1815739 and MTHFR rs1801131 were associated with sarcopenic obesity, while in Urzi et al. [1], ACTN3 rs1815739 and MTHFR rs1801131 were significantly linked to sarcopenia risk, emphasizing the need for tailored interventions to address obesity-related and age-related muscle decline.