Gene sequencing as a diagnostic tool in multiple endocrine ncoplasia type

present in these three exons. Over 95% of cases of MEN (Multiple Endocrine Neoplasia) 2A and 85% of cases of FMTG (Familial Medullary Thyroid Carci- noma) have mutations in exons 10 and 11. A point mutation in exon 16 is present in over 95% of cases of MEN 2B. The test is cost effective and results can be reported in less than 24 hours. It requires 200 pJ of blood from the patient in order to extract genomic DNA which is used to amplify the three RET exons by PCR (Polymerase Chain Reaction). The PCR product serves as the template for sequencing. In a blind study, the assay was utilized to characterize I 3 samples previously identified as normal or representative ofseveral examples of mutations. The study results showed 100% accuracy. The detection of these mutations allows early diagnosis of patients with MEN 2A, MEN 2B, and FMTG so that appropriate measures can be taken to prevent the development of thyroid mcd- ullarv cancer.