Abstract 142: Endocrine neoplasia type 2B with a rare mutation: A case report

Introduction: Multiple Endocrine Neoplasia (MEN) type 2 is a rare familial endocrine syndrome. MEN 2B syndrome, the least common subtype of MEN 2 syndrome, is characterized by medullary carcinoma of thyroid (MTC), pheochromocytoma and absence of hyperparathyroidism. Identifying the responsible mutation have prognostic consequences. Majority of MEN2B cases occur due to de-novo mutation with 95% cases involving codon 918, and codon 883, 2-3% cases. Objective: Identification of the genetic mutation in patient presented with MTC, and bilateral adrenal pheochromocytoma. Methods: Whole Exome Analysis was performed to identify the genetic defect. The variants were prioritized using standard open-source computational pipelines. Results: Whole exome sequencing and computational analysis identified a non-synonymous single nucleotide polymorphism T1991C in the exon 13 of RET gene on chromosome 10, resulting in a missense mutation (p.M664T) in the protein responsible for phenotypic expression known as MEN 2B syndrome. Conclusion: MTC and bilateral pheochromocytoma are indications for detailed clinical and genetic examination of the proband. Bilateral adrenalectomy, followed by total thyroidectomy and prophylactic central neck dissection was done along with lifetime hormone supplementation. This is a rare mutation reported in MEN2B (A Rare Syndrome) which usually involve codon 918 and 883.