Abstract 48: A typical neurofibromatosis type 1 presenting as overgrowth syndrome

A 6 years old boy presented to the endocrinology department as unilateral left leg overgrowth since birth. Limb discrepancy had been negligible at birth but became evident as the child gained height and further he developed a limping gait by 2 years of age. On examination, he had multiple café au lait spots of > 5 mm over the body and hyperpigmentation on anterolateral aspect of left leg which turned out to be a venous malformation on color Doppler and MRI of the leg. There was no other neuro cutaneous marker and no family history of similar illness or any other neuro cutaneous lesions or any abdominal malignancy. A probable diagnosis of segmental overgrowth syndrome was made with associated café au laits. We wanted to rule out syndromic cause for the same, so patient was advised clinical whole exome sequencing. Genetic result revealed atypical NF1 with heterogenous 3’ splice site variation in intron 36 of the NF1 gene. We hereby report rare presentation of neurofibromatosis as segmental overgrowth syndrome.