Abstract 87: Novel mutation in leptin receptor causing monogenic obesity

Hereby we present a case of monogenic obesity in a 3 ½ year old boy. Child was born of third degree consanguinity with birth weight of 3kg. He had excessive weight gain since five months of age with food seeking behaviour, recurrent upper respiratory tract infections since infancy, renal calculi and features of obstructive sleep apnoea. He had normal developmental milestones. His 5 ½ year old sister also had obesity since infancy with a present BMI of 41.64 kg/m2 and recurrent upper respiratory tract infections. No other similar family history. On examination, his height was 103 cm (SDS 0.98). He weighed 40 kg with BMI of 37.7 kg/m2 (Z score +6.9). General examination showed grade 4 acanthosis nigricans, low set ears, and café au lait spot on the abdominal wall. Bone age was appropriate for chronological age. Investigations revealed dyslipidemia and fatty hepatomegaly. Screening tests for secondary causes were negative. In view of strong suspicion of genetic etiology, clinical exome sequencing was done which showed a novel mutation c.850-1G>A in Intron 7 of LEPR suggestive of leptin receptor defect.