Endocrine Abstracts

The case: The multiplex endocrine neoplasia 2A (MEN2A) syndrome is a monogenic disease caused by mutation of the RET protooncogene leading to medullary thyroid cancer (MTC), pheochromocytoma and primary hyperparathyroidism. The specific mutations determine the timing of the preventive thyroidectomy. In 2007, in a 26 year old female patient, after detailed endocrine investigation, total thyroidectomy with both sided lateral neck lymph node dissection was performed because of suspicion of medullary thyroid cancer. The final histology proved the diagnosis. Three years later hypertensive peaks occured, pheochromocytoma was found and removed by laparoscopic adrenalectomy. The family was screened for MEN2A. The mutation TGC634TTC(Cys634Phe) of the codon 634 was found in the patient, in her father and one brother. After spontaneous conception and normal pregnancy in October 2012 she gave birth to a boy. The son was screened for MTC with calcitonin with the age of 11 and 13 months (15.6–18 pg/ml) and was proven to be RET positive. Preventive total thyroidectomy and partial parathyroidectomy was done with the age of 18 months. The final histology found no sign of medullary thyroid cancer or primary hyperparathyroidism. As the patient did not want to have another child affected by the disease, application of assisted reproductive technologies were recommended. After ovarian stimulation, 4 embryos were biopsied in trophectoderm stage. Karyomapping (preimplantational genetic screening for chromosomal abormalities and preimplantational genetic diagnostics for the specific mutation) was performed revealing one healthy and three MEN2A affected embryos, two of them with maternal aneuploidy aswell.

Conclusion: For the monogenic disease affected families, it is important to offer the possibility of preimplantation genetic diagnosis to exclude the affected embryos to be transfered. Healthy children don’t require lifelong endocrine follow-up and operations, and no psychological support.