Background: The melanocortin-4-receptor gene (MC4R) is a key regulator of energy homeostasis, food intake and body weight which has intensively been analyzed in molecular genetic obesity research. MC4R dysfunction in humans causes hyperphagia, impaired satiety and obesity.
Objective and hypotheses: To identify MC4R mutations prevelance in Turkish obese children and adolescents.
Method: Ninenty three pediatric and adolescent patients aged between 1.3 and 15 years old with early onset obesity (45 female/48 male) were enrolled. Obesity was defined as a body mass index (BMI) standart deviation score (SDS) of +2.0 according to the Turkish Population. Children with genetic syndromes associated with obesity or mental retardation, or taking drugs that promote changes in eating behavior or weight were excluded. Coding region of the MC4R gene was sequenced by Illumina MiSeq Next Generation Sequencing System.
Results: The mean age of the patients was 7.3±3.7 years and mean BMI was SDS 3.7±0.7SD. Seventy nine patients (85%) were prepubertal, and 14 patients (15%) were pubertal. We identified four different mutations in eight patients, giving a mutation detection rate of 8.6%. Of these, three were previously identified missense mutations p.N274S, p.S136F and p.V166I). One was a novel homozygous mutation p.I291SfsX10 (c.870delG) detected in a severely obese 2-year-old boy. By in-silico analysis softwares this novel mutation predicted to be disease causing and it is expected to have a-32 aminoacids shorter MC4R protein.
Conclusion: MC4R gene mutations is quite common in childhood obesity in Turkish population. Investigating the mutations in MC4R gene in patients with severe childhood-onset obesity is necessary.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology