제2B형 다발성 내분비 선종에 대한 RET 유전자의 점돌연변이 분석

Background and Objective: Multiple Endocrine Neoplasia type 2B (MEN 2B) is a syndrome associated with medullary thyroid carcinoma, pheochromocytoma, ganglioneuromatosis, marfanoid features and skeletal abnormalities. Since MEN 2B is an autosomal dominant disorder, early detection and treatment is crucial. Genetic analysis of RET proto-oncogene in a patient diagnosed as MEN 2B is reported. Materials and Method: A patient diagnosed as MEN 2B was studied at the department of Otolaryngology-Head and Neck Surgery at a tertiary hospital in 1992. Initially, DNA was extracted from the peripheral blood leukocyte of the patient and PCR amplification of exons 10, 11, 13, 14, 15, 16 was performed, followed by investigation of point mutation on RET proto-oncogene using DNA sequence analyzer. Results: The automatic DNA sequence analyzing method revealed normal findings at exon 10, 11, 13, 14, 15 while point mutation of ATG (Met) to ACG (Thr) at codon 918 of exon 16 at RET proto-oncogene. Conclusion: The author could identify the point mutation in a patient with MEN 2B by performing a genetic analysis of RET proto-oncogene. Although MEN 2B may be extremely rare it shows the worst prognosis and is inherited. Thus, the result of this study showing the mutations in this disease may be useful for genetic councelling. With genetic analysis of RET proto-oncogene, limitations of the conventional calcitonin stimulation test may be overcome. Moreover, the approach could be more ultimate and comprehensive through early diagnosis by carrying out this screening test for point mutations in the family members of the patient with MEN 2B. (J Clinical Otolaryngol 2007;18:79–85)