hrp0092p1-196 | Fat, Metabolism and Obesity (1) | ESPE2019

Why are Patients with Obesity Due to Leptin Receptor Deficiency not Sufficiently Recognized? Prevalence Estimation Based on European Allele Frequencies and Thoughts on the Discrepancy

Kleinendorst Lotte , Abawi Ozair , van den Akker Erica , Van Haelst Mieke

Background: Biallelic loss of function (LoF) mutations in the leptin receptor gene (LEPR) cause a striking phenotype of early-onset severe obesity and hyperphagia. Additionally, hypogonadotropic hypogonadism, growth hormone deficiency, and/or hypothyroidism are often present. Currently, 19 European patients (all aged <30 years) are described in literature. As clinical trials investigating MC4R-agonist treatment are performed throughout Europe, ide...

hrp0097p2-279 | Late Breaking | ESPE2023

The narrative of a patient with leptin receptor deficiency: personalized medicine for a rare genetic obesity disorder

S. Welling Mila , Kleinendorst Lotte , M. van Haelst Mieke , L.T. van den Akker Erica

Leptin receptor deficiency is a rare genetic disorder that affects the body’s ability to regulate appetite and weight. For patients and their families, the disorder seriously disrupts daily life, however, little is published about this impact. We here report the experiences of a 10.5-year-old girl with leptin receptor deficiency and her family. The diagnosis of this rare genetic obesity had a deep impact on the life of the child and her family. It led to a better underst...

hrp0092p1-46 | Fat, Metabolism and Obesity | ESPE2019

How to Recognize Underlying Somatic Causes of Paediatric Obesity? Performance of the Diagnostic Recommendations of the Endocrine Society Guideline and Suggestions for Improvement

Abawi Ozair , Kleinendorst Lotte , van der Voorn Bibian , Brandsma Annelies , van Rossum Elisabeth , van Haelst Mieke , van den Akker Erica

Background: Underlying causes of obesity are thought to be rare even in specialized paediatric endocrinology clinics. However, evidence is limited. The Endocrine Society (ES) guideline for paediatric obesity makes the following diagnostic recommendations: endocrine evaluation in presence of reduced growth velocity, evaluation of cerebral obesity in presence of CNS injury, re-evaluation of drug choice in patients using antipsychotics. Genetic testing is recomme...

hrp0092p1-47 | Fat, Metabolism and Obesity | ESPE2019

How Early is 'extreme Early-Onset Obesity'? Results of Comprehensive Growth Curve Analysis to Identify Genetic Obesity Disorders Based on Age of Onset of Obesity

Abawi Ozair , Kleinendorst Lotte , Blankers Lizette , van Haelst Mieke , van der Voorn Bibian , van den Akker Erica

Background: Early-onset obesity is associated with genetic obesity disorders. According to the Endocrine Society guideline for paediatric obesity, genetic screening is indicated in selected cases with age of onset (AoO) of obesity <5 years. However, this cut-off value lacks evidence. Identifying genetic obesity is vital as treatment for leptin-melanocortin pathway disorders becomes available. We aimed to determine whether AoO of obesity is predictive for g...

hrp0098p1-42 | Fat, Metabolism and Obesity 1 | ESPE2024

Unravelling the relationship between Head Circumference and Melanocortin4-Receptor deficiency from infancy to adulthood: a case-control study

E.P.L. van der Walle Eline , J. de Groot Cornelis , S. Welling Mila , Kleinendorst Lotte , M. van Haelst Mieke , L.T. van den Akker Erica

Background: Melanocortin4-receptor (MC4R) deficiency is the most common cause of monogenetic obesity. Other forms of genetic obesity, like 16p11.2 deletion syndrome, are associated with increased head circumference (HC). Little is known about HC in patients with MC4R deficiency.Methods: This study included patients with homozygous or heterozygous, pathogenic or likely pathogenic ACMG class 4 or 5 MC4R variants. Pediatric...

hrp0097lb5 | Late Breaking | ESPE2023

Clinical phenotyping of patients with genetic obesity

S. Welling Mila , Mohseni Mostafa , E.H. Meeusen Renate , R. Boon Mariëtte , J. de Groot Cornelis , M. van Haelst Mieke , A. Visser Jenny , L.T. van den Akker Erica , F.C. van Rossum Elisabeth

Introduction: In rare cases of obesity, genetic defects lead to hyperphagia and severe early-onset obesity. Genetic testing in patients with a suspected genetic obesity phenotype is important, as it can lead to patient-tailored treatment advice. For children, the Endocrine Society (ES) recommends genetic testing in children with early-onset of obesity (<5 years) and hyperphagia. It is unclear whether these recommendations can also be used in adult obesity c...