ESPE Abstracts

Background: Childhood-onset obesity is a multifactorial disease with a lifelong health burden. In many cases, obesity is the result of the interaction between genetic predisposition and environmental factors. Aim of our study was to define phenotypic features of obese children and adolescents and to find possible associations between clinical phenotype and genetic variants.

Patients and Methods: We recruited obese children followed at our centre, who underwent obesity NGS panel (roadgenetics.unilabsweb.com). Genetic variants were defined as pathogenetic or variants of unknown significance (VOUS); VOUS were classified into 3 categories: suspected pathogenetic, uncertain, and suspected benign. We defined as “negative” patients with no variant, “positive” patients with any potentially relevant variant; we then defined as “suspected pathological” patients carrying pathogenetic variant(s) or suspected pathogenetic or uncertain VOUS, while patients with negative test or suspected benign VOUS were defined as “normal”. Clinical data were analyzed and compared to genetic findings.

Results: 25 patients (12M,3F) were enrolled between May, 2022 and March, 2023. Median age at blood sampling was 10.78 years (1^st-3^rd quartile 7.47-13.07years). Median age at obesity onset was 3.2 years (1.4-4.4years). Hyperphagia was reported by only 9 subjects. Median BMI was 33.8Kg/m² (27.6-38.8), median BMI SDS +3.60 (3.17-4.10). Median height SDS was +0.5 (-0.5-+2.0), while median delta between height and mid-parental height was +0.9 SDS (0.2-1.4) A positive genetic test was found in 18 patients(72%), while 11 patients(44%) had a suspected pathological genetic test. Median BMI SDS did not differ significantly between patients with a positive genetic test compared to negative genetic test (3.65 vs 3.58, P=0.16), nor between patients with suspected pathological findings and patients with normal result (3.68 vs 3.51, P=0.67). A trend towards higher height SDS was found in subjects with a suspected pathological test compared to normal tests (2.00 vs 0.25, P=0.07). No significant relation was found between height-mid-parental height SDS delta and genetic findings. Age at obesity onset did not differ significantly in patients with positive or negative genetic test(2.0 vs 4.7years, P=0.14), or in patients with suspected pathological or normal genetic test(3.0 vs 4.0 years, P=0.65)

Conclusion: Our preliminary findings in a small cohort of obese children support the hypothesis that no clinical feature – e.g. degree of obesity, age at disease onset, stature, or difference between stature and mid-parental height – predicts the presence of genetic variants in obese children.