Vázquez-Moreno M, Locia-Morales D, Perez-Herrera A, et al. - Using the Wald and inverse variance weighting methods, researchers conducted Mendelian randomization analysis to examine the correlation of HP rs2000999 with serum haptoglobin and childhood and adult obesity in up to 540/697 and 592/691 Mexican cases and controls, respectively. Anthropometric and biochemical data have been obtained. A positive association was found between HP rs2000999 G allele and haptoglobin level in children and adults. HP rs2000999 G allele was linked positively to childhood but not to adult obesity. For the first time in the Mexican population, the evidence shows a causal positive correlation between serum haptoglobin level and childhood obesity. The research contributes to the genetic elucidation of childhood obesity and suggests haptoglobin as an effective biomarker and target of obesity treatment.