Copy Number Variation Analysis Increases the Number of Candidate Loci Associated with Pediatric Obesity

Background/aims: Obesity is a multifactorial disease caused by the interaction of genetic, environmental, and behavioral factors. Currently, only a small number of obese children undergo genetic analysis, usually when obesity is associated with dysmorphic features. The aim of this study was to identify genomic rearrangement causing obesity.

Methods: We analyzed the DNA of children and adolescents by single-nucleotide polymorphism-array (platform CytoScan HD, Affymetrix). Patients included in this study were obese with dysmorphic features and/or intellectual disabilities and/or neuropsychomotor signs.

Results: Ninety-four children and adolescents with obesity (9.25 ± 4.04 years old, 60 males) were enrolled in the study. Dysmorphic features were found in 64 out of 94 subjects (68.1%), intellectual disability was found in 23 subjects (24.5%), and other neuropsychomotor signs in 31 (32.9%). Copy number variations (CNVs) were identified in 43 out of 94 patients (45.7%): among these 14 subjects showed at least 1 deletion, 22 duplication, whereas 7 patients showed both deletion and duplication. In 20 subjects (13 males), CNVs were linked or possibly related with obesity; in 23 subjects, this correlation cannot be inferred.

Conclusion: A genetic origin of obesity was detected in about half of our obese children and adolescents with associated dysmorphic features and/or intellectual disability and/or neuropsychomotor signs. In these children, array-CGH analysis can be useful to identify causative genetic mutations, with consequent advantage in therapeutic management and follow-up of these patients.