GENETIC SCREENING FOR MEN 2A IN ROMANIA: DIAGNOSIS OF A FAMILY WITH A CYS634PHE MUTATION OF THE RET GENE

1 Department of Endocrinology of the University of Medicine and Pharmacy "Victor Babes" Timisoara, Romania, 2Section of Preventive Medicine, Department of Nephrology, University of Freiburg Medical Centre, Freiburg im Breisgau, Germany, 3Department of Pathology of the University of Medicine and Pharmacy "Victor Babes" Timisoara, Romania
Background: Genetic testing for screening at-risk members of MEN 2 families is only recently available in Romania. Aim: Here we present the diagnostic pathway through which the germ-line RET proto-oncogene mutation TGC > TIC at codon 634 (Cys634Phe) was identified in a Romanian family with MEN 2A phenotype.

Methods: The index case is a woman who was clinically diagnosed with MEN 2A phenotype including bilateral pheochromocytoma and medullary thyroid carcinoma which were surgically treated. Family history taken from the patient revealed other affected members in the kindred. The patient and other two first-degree relatives were genetically analyzed after giving their written consent. Genomic DNA from peripheral blood leukocytes was extracted using the standard techniques. Amplification through polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP) and denaturing high performance liquid chromatography (DHPLC) of exons 10, 11 and 13 of the RET gene was performed.

Results: Abnormal pattern was found in SSCP and DHPLC and direct sequencing of exon 11 showed the mutation at codon 634 TGC> TIC (Cys634Phe). The two relatives of the index patient were found positive for the same RETmutation. Consecutively, they were clinically screened for phenotypic determination by biochemical measurements including calcitonin, urinary metanephrines and normetanephrines, and imagistic methods such as ultrasound thyroid evaluation and abdominal MRl.lncreased basal calcitonin levels were found in both, and total thyroidectomy was indicated in conformity to the international consensus recom mendations.

Conclusion:
These two relatives of the MEN 2A Cys634Phe patient are the first cases that were managed on the basis of genetic screening at the Clinic of Endocrinology in Timisoara, Romania.