ESPE Abstracts

Background: Leptin receptor deficiency leads to severe early-onset obesity and pituitary dysfunction. Here we present the first case of monogenic obesity due to a novel mutation in LEPR gene in Russia.

Case report: 16-year-old female patient was admitted to our hospital with morbid obesity and primary amenorrhea. She was born at term with a birth weight of 3360 g to non-consanguineous parents. She had a mild developmental delay in early childhood. From the first months of life girl had excessive appetite and rapid weight gain: at 3 month she was 7 kg, at 1 year 20 kg, at 9 years 99 kg, at 15 years 161 kg. At the age of 9 she was first diagnosed as insulin resistant (HOMA-IR 11.8) and hypertensive. The recommendation of dietary and life-style intervention was not helpful and due to overweight, insulin resistance progression type 2 diabetes developed (HbA1c 8.9%). Metformin and hypotensive therapy had been administered. At 16 she was hospitalized in emergency with glycemia of 22 mmol/l, HbA1c was 15.3% so insulin Glargin was added to the therapy. By physical examination at 16 years: morbid obesity (weight 159kg, SDS IBM 4.75), Tanner stage 2. Investigation indicated dyslipidemia, steatohepatitis, lipomatosis and arterial hypertension. Combination therapy with metformin and insulin improved glycemic control and reduced HbA1c level to 6.5%. LHRH test demonstrated a pre-pubertal response. Other endocrine abnormalities were not found. The presence of severe early-onset obesity with hypogonadotropic hypogonadism and high levels of leptin (157 ng/ml (3.7-11.1) led to the suspicion of leptin receptor deficiency. Genetic testing identified two pathogenic variants in LEPR gene: exon4:c.131_132insTGAC:p.Y46X and c.2588_2589delCA:p.H864fsX24 in exon18. Healthy mother was found to be a heterozygous carrier of the c.2588_2589delCA:p.H864fsX24 variant.

Conclusion: Early genetic testing can improve diagnosis of rare monogenic forms of obesity and identify patients whose quality of life can be improved. Targeted therapeutic intervention can protect them from getting obesity complications.