ABCB1 and obesity due to melanocortin 4 receptor deficiency: Additionally, five heterozygous novel gene variants of the <i>ANKK1</i>, <i>NEGR1</i>, <i>OGDH</i>, <i>ABCB1</i>, and <i>GSK3B</i> genes were identified, which are predicted to cause excessive fat accumulation and disruption of energy balance in individuals.<h4>Conclusions</h4>We suggest that the cumulative effects of all obesity-associated detected variants lead to the early-onset obesity phenotype observed in individuals.