Endocrine Abstracts

Background and objectives: Certain diseases, such as multiple endocrine neoplasia type 2A (MEN2A), MEN2B, familial and sporadic medullary thyroid carcinoma (MTC) and renal dysgenesis are related to abnormalities of the RET protein. Our aim was to evaluate the frequency of RET mutation in ten Saudi families with MEN2A and familial medullary thyroid carcinoma.

Design and setting: Cross-sectional prospective study of patients followed up at King Abdul-Aziz University Hospital and King Abdul-Aziz Medical City, Jeddah between March 2001 and March 2011.

Patients and methods: Genomic DNA was isolated from peripheral blood leucocytes of all the subjects using standard procedures. Exons 10, 11, 13, 14 and 16 of the RET proto-oncogene were analyzed by single-strand conformation polymorphism, direct DNA sequencing and/or restriction enzyme analysis. Statistical analysis was performed using the Statistical Package for the Social Sciences.

Results: Seventy-nine subjects were screened for RET mutation. Forty-three of the subjects with hereditary MTC were enrolled in this study. MEN2A was identified in 25 cases; MTC was diagnosed in all 25 cases (100%), pheochromocytoma in 13 cases (52%) and hyperparathyroidism in 4 cases (16%). The most frequent genotype in patients with MEN2A syndrome was codon 618 mutation (46.6%), followed by 634 mutation (44.2%). Among the five families with MEN2A, three had a mutation at codon 634, while two had a mutation at codon 618.

Conclusion: The most frequent RET proto-oncogene mutation in our series was in codon 618 (exon 10).