TCF7L2 and obesity due to melanocortin 4 receptor deficiency: A recent study that followed obese metabolically healthy patients for over 15 years identified a statistically significant association between single-nucleotide polymorphisms and this obesity phenotype in women, specifically for the FTO (rs1121980), TCF7L2 (rs7903146), and SLC39A8 (rs13107325) genes [10].