RET proto-oncogene mutation analysis in a pedigree with multiple endocrine neoplasia 2A

Objective To discuss clinical diagnosis and treatment of multiple endocrine neoplasia ( MEN) 2A,and report the mutation of RET proto-oncogene in a pedigree of three patients with MEN 2A. Methods Bilateral adrenalectomy was performed on two of the three

C634Y mutation in RET-induced multiple endocrine neoplasia type 2A:A case report

BACKGROUND Multiple endocrine neoplasia type 2(MEN2)is a rare,autosomal dominant endocrine disease.Currently,the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis.Once an RET carrier is detected,family members should be screened to enable early detection of medullary thyroid carcinoma,pheochromocytoma,and hyperparatitity.Among these,medullary thyroid carcinoma is the main factor responsible for patient mortality.Accordingly,delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners.CASE SUMMARY Herein,we present RET proto-oncogene mutations,clinical characteristics,and treatment strategies in a family with MEN2A.A family study was conducted on patients diagnosed with MEN2A.DNA was extracted from the peripheral blood of family members,and first-generation exon sequencing of the RET protooncogene was conducted.The C634Y mutation was identified in three family members spanning three generations.Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas.A 9-yearold child harboring the gene mutation was diagnosed with medullary thyroid carcinoma.Surgical resection of the tumors was performed.All family members were advised to undergo complete genetic testing related to the C634Y mutation,and the corresponding treatments administered based on test results and associated clinical guidelines.CONCLUSION Advancements in MEN2A research are important for familial management,assessment of medullary thyroid cancer invasive risk,and deciding surgical timing.

Molecular diagnostic approaches in detecting rearranged during transfection oncogene mutations in multiple endocrine neoplasia type 2

Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during transfection(RET)gene changes the way that receptor tyrosine kinases work.Multiple endocrine neoplasia,a pathological condition,involves these kinases.When the RET protooncogene changes,it can cause endocrine adenomas and hyperplasia to happen at the same time or one after the other.Pheochromocytoma,medullary thyroid carcinoma,and hyperparathyroidism,alone or in combination,are present in MEN2A patients.Some patients may also have skin lichen amyloidosis or Hirschsprung's disease.Patients with MEN2A often present with MTC.MTC is aggressive and has the worst prognosis,as most patients exhibit lymph node metastasis.MTC is one of the important causes of death in patients with MEN2A.RET mutation analysis aids in identifying MEN2A symptoms and monitoring levels of calcium,thyroid hormones,calcitonin,normetanephrine,fractionated metanephrines,and parathyroid hormone.The earlier diagnosis of MTC significantly improves survival and prompts better management of MEN2A.In this editorial,we will discuss the significance of molecular diagnostic approaches in detecting RET oncogene mutations in MEN2A.

A NOVEL Ser73Gly VARIATION OF SUCCINATE DEHYDROGENASE,SUBUNIT D AND A Cys634Gly MUTATION IN Ret PROTO-ONCOGENE OBSERVED IN A CHINESE MULTIPLE ENDOCRINE NEOPLASIA TYPE 2A PATIENT

Multiple endocrine neoplasia type 2A （ MEN2A ） is an autosomal dominant cancer syndrome that is characterized by medullary thyroid carcinoma （MTC）, pheochromaocytoma （50% - 60% of cases ）, and hyperplasia of the parathyroid glands （ 20% - 30% of cases ）. MEN-2A comprises a heterogeneous group of neoplastic disorders that most commonly have a single missense substitution of the Ret proto-oncogene （RET） involving exons 10 and 11. Here, we reported a novel case of MEN2A associated with two variations in two distinct genes, Cys634Gly in RET and a rare Ser73Gly substitution in succinate dehydrogenase, subunit D （SDHD）. Because the patient presented with medullary thyroid carcinoma and pheochromocytoma but without parathyroid gland involvement, we speculated that this clinical feature could be correlated with the two substitutions. This is the first report of a MEN2A case involving two different changes one in the RET gene and the other in the SDHD gene.

Is new American Thyroid Association risk classification for hereditary medullary thyroid carcinoma applicable to Chinese patients? A single-center study

Objective: The American Thyroid Association (ATA) proposed a new risk classification for hereditary medullary thyroid carcinoma (MTC) in 2015. This study aimed to assess whether the new guidelines are suitable for the Chinese population, and reported our experience on prophylactic thyroidectomy. Methods: A total of 73 patients from 22 families were screened as rearranged during transfection (RET) mutation carriers from 2010 to 2016 in Cancer Hospital, Chinese Academy of Medical Science; the medical history for each patient was collected. Based on the initial treatment, we identified the risk factors for poor prognosis by univariate and multivariate logistic regression. Then, 4 RET mutation carriers were enrolled for prophylactic thyroidectomy, and their pathological data and follow-up outcomes were recorded. Results: In univariate and multivariate logistic regression analyses, age at initial surgery and risk classification were significant risk factors for stage III/IV hereditary MTC at initial diagnosis. The likelihood was increased by 11.6% per year of age at initial surgery [95% confidence interval (95% CI), 1.040-1.198; P=0.002). It was 7.888 times more likely to have III/IV stage disease for ATA highest risk patients, compared to ATA moderate risk individuals (95% CI, 1.607-38.717; P=0.003). Postoperative pathological results showed all 4 multiple endocrine neoplasia type 2A (MEN2A) patients had C-cell hyperplasia (CCH); multifocal malignancies were detected in 3 of them. All 4 patients were cured biochemically, and none developed permanent hypoparathyroidism. Conclusions: In Chinese individuals, hereditary MTC aggressiveness is in line with the new ATA risk classification. Germline RET gene mutation carriers should undergo prophylactic thyroidectomy according to basal serum calcitonin levels.