Multiple endocrine neoplasia-IIb (MEN-IIb) is a rare hereditary autosomal dominant syndrome caused by mutations in the RET proto-oncogene. It's characterized by medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), mucosal neuromas, and Marfanoid habitus. Because of the rarity of MEN-IIb and finiteness of clinical cognition, the majority of the patients suffer a delayed diagnosis. A MEN-IIb patient with the lingual mucosal neuromas since childhood was admitted in the Third Xiangya Hospital of Central South University in November, 2018. He had surgical history of mitral valve prolapse and spinal deformity. He was diagnosed with MTC and PHEO at the age of 22 and 28, respectively, and received surgical treatments. Sequencing of RET gene revealed a de novo heterozygous p.M918T mutation in the patient. Being aware of the unique clinical phenotype and screening of RET gene mutation may lead to the early diagnosis and better long-term outcome for MEN-IIb.
Adrenal Gland Neoplasms ; Child ; Genes ; Humans ; Male ; Multiple Endocrine Neoplasia ; Multiple Endocrine Neoplasia Type 2a/genetics* ; Multiple Endocrine Neoplasia Type 2b/genetics* ; Mutation ; Proto-Oncogene Proteins c-ret/genetics* ; Thyroid Neoplasms/genetics*

Objective: To investigate the correlation between CLOCK and BMAL1 genes and MEN2 medullary thyroid carcinoma (MTC). Methods: Thirteen cases with MEN2 MTC and thirteen cases with non-MEN2 MTC were selected who were treated in the Yantai Yuhuangding Hospital between January 2013 and September 2021. Clinical indicators such as blood calcitonin level, tumor diameter and metastatic lymph node of patients were collected. The expression differences of CLOCK and BMAL1 between MEN2 MTC and para-carcinoma tissue as well as between MEN2 MTC and non-MEN2 MTC were detected by immunohistochemistry and qPCR. The correlation between lymph node metastasis and CLOCK or BMAL1 expression was analyzed. Protein-protein interaction (PPI) network analysis combined with qPCR and correlation analysis was used to explore the expression regulation relationship between RET and circadian clock genes. The rhythm disorder of MEN2 cells was verified by lipopolysaccharide cell stimulation experiment after dexamethasone rhythm synchronization. Results: MEN2 MTC exhibited typical RET gene mutation. The mean blood calcitonin level, the tumor diameter and the number of metastatic lymph nodes of patients with MEN2 MTC were higher than those of patients with non-MEN2 MTC (t value was 2.76, 2.53, 2.26, all P<0.05). Immunohistochemical results showed that the expression levels of CLOCK and BMAL1 in MEN2 MTC were higher than those in non-MEN2 MTC, while negatively expressed in para-cancerous thyroid follicle. qPCR displayed that the expression of CLOCK gene in cancer tissues was higher than that in non-MEN2 MTC and para-cancerous tissues (t value was 2.68 and 2.86, all P<0.05); the expression of BMAL1 gene in MEN2 MTC was higher than that in non-MEN2 MTC and para-cancerous tissues (t value was 2.21 and 2.35, all P<0.05). Correlation analysis showed that the expression levels of CLOCK and BMAL1 genes were positively correlated with the number of lymph node metastases in patients with MEN2 MTC (r=0.65, P<0.001; r=0.52, P=0.005). PPI network analysis indicated that the expression of CLOCK gene was positively correlated with the abnormal expression of RET gene (r=0.96, P<0.001). With lipopolysaccharide to stimulate cultured cells in vitro after dexamethasone rhythm synchronization, the expressions of CLOCK and BMAL1 in MEN2 MTC cells (0.47±0.22 and 2.60±1.48) at 12 hours of synchronization were significantly lower than those in para-cancerous tissues (1.70±1.62 and 8.23±2.52), the difference was statistically significant(t=5.04, P=0.007; t=3.34, P=0.029). Conclusion: CLOCK and BMAL1 are correlated with the occurrence and development of MEN2 MTC, and may be potential targets for the development of new therapeutic strategies for MEN2 MTC.
ARNTL Transcription Factors/genetics* ; CLOCK Proteins/genetics* ; Calcitonin ; Carcinoma, Neuroendocrine/genetics* ; Dexamethasone ; Humans ; Lipopolysaccharides ; Lymphatic Metastasis ; Multiple Endocrine Neoplasia Type 2a/genetics* ; Thyroid Neoplasms/surgery*

Objective: To explore the reasonable time of prophylactic thyroidectomy for RET gene carriers in multiple endocrine neoplasia(MEN) 2A/2B families. Methods: From May 2015 to August 2021, RET gene carriers in MEN2A/MEN2B families were dynamically followed up at the Department of Thyroid Head and Neck Surgery, Beijing Tongren Hospital of Capital Medical University. The high-risk patients were encouraged to undergo prophylacitc total thyroidectomy according to the principle of "graded early warning system", namely the evaluation of gene detection, calcitonin value and ultrasound examination successively. Seven cases underwent the surgery, including 3 males and 4 females, aged from 7 to 29 years. According to the risk stratification listed in the guidelines of the American Thyroid Association in 2015, there were 2 cases of the highest risk, 2 cases of the high risk and 3 cases of the modest risk. Calcitonin index remained within the normal range in 3 cases and elevated in 4 cases before operation. All 7 patients underwent thyroidectomy with lymph node dissection of the level Ⅵ performed in 4 patients. Results: The time from suggestion to operation was 2 to 37 months, with an average of 15.1 months. The 6 patients were medullary thyroid carcinoma and 1 case with C-cell hyperplasia. The follow-up time was 2 to 82 months, with an average of 38.4 months. Postoperative serum calcitonin levels of all cases decreased to normal level, with biochemical cure. There was no sign of recurrence on ultrasound examination. All 7 patients had no serious complications, no obvious thyroid dysfunction. Their height, weight and other indicators of pediatric patients were similar to those of their peers, with normal growth and development. Conclusion: For healthy people with MEN2A/MEN2B family history, prophylactic thyroidectomy can be carried out selectively based on the comprehensive evaluation of "graded early warning system" with strict screening and close monitoring.
Female ; Male ; Humans ; Child ; Adolescent ; Young Adult ; Adult ; Multiple Endocrine Neoplasia Type 2b/surgery* ; Thyroidectomy ; Multiple Endocrine Neoplasia Type 2a/surgery* ; Calcitonin ; Germ-Line Mutation ; Proto-Oncogene Proteins c-ret/genetics*

Adult ; Carcinoma, Neuroendocrine ; Female ; Genetic Testing ; Humans ; Multiple Endocrine Neoplasia Type 2a ; genetics ; Proto-Oncogene Proteins c-ret ; genetics ; Thyroid Neoplasms ; genetics

OBJECTIVETo identify the genotype of RET gene in one multiple endocrine neoplasia type 2A (MEN2A) kindred.

METHODSGenome DNA was extracted from peripheral blood leucocytes. The DNA sequence of gel-purified polymerase chain reaction (PCR) products was determined with the previously reported 6 pairs of primers of PCR amplification of 10, 11, 13, 14, 15, and 16 exons of RETgene.

RESULTSNo abnormalities were found in exon 10, 13, 14, 15, and 16. C to G replacement in nucleotide 14 996 of exon 11 was identified in DNA samples obtained from both peripheral blood of 2 affected brothers. This missense point mutation arisen in heterozygosity and caused a substitution of Cys to Trp residue at codon 634 ( Cys 634 Trp) in RET protein.

CONCLUSIONThe genotype of the family is identified as Cys 634 Trp substitution of RET gene.

Adult ; Exons ; genetics ; Female ; Humans ; Male ; Multiple Endocrine Neoplasia Type 2a ; genetics ; Pedigree ; Point Mutation ; Polymerase Chain Reaction ; Proto-Oncogene Proteins c-ret ; genetics

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant hereditary neuroendocrine cancer syndrome characterized by medullary thyroid carcinoma, in combination or not with pheochromocytoma, hyperparathyroidism and extra-endocrine features, and two forms subtyped as MEN2A and MEN2B. Based on the correlation between RET proto-oncogene mutation and MEN2 phenotype, MEN2 could be prevented through prenatal diagnosis and preimplantation genetic testing. Integrating the detection of RET mutation with measurement of serum calcitonin, plasma or urinary metanephrine/normetanephrine, and serum parathyroid hormone levels could accurately predict the progression of MEN2, and then facilitating implementation of personalized precision treatment. In addition, increased awareness of MEN2 is needed, which requires participation of physicians, patients/family members, and relevant organizations, supplemented by psychological support, which could promote the comprehensive management of MEN2. The "5P" strategies for MEN2 represents a paradigm of precision medicine, which could effectively avoid or reduce the clinical adverse outcomes, improve the prognosis and quality of life of MEN2 patients.
Humans ; Multiple Endocrine Neoplasia Type 2a/therapy* ; Quality of Life ; Proto-Oncogene Proteins c-ret/genetics* ; Early Detection of Cancer ; Thyroid Neoplasms/genetics* ; Adrenal Gland Neoplasms/therapy*

Adult ; Base Sequence ; Carcinoma, Medullary ; congenital ; genetics ; surgery ; Female ; Genetic Testing ; Humans ; Male ; Molecular Sequence Data ; Multiple Endocrine Neoplasia Type 2a ; genetics ; surgery ; Proto-Oncogene Proteins c-ret ; genetics ; Thyroid Neoplasms ; genetics ; surgery

OBJECTIVETo explore the clinical characteristics and significance of RET proto-oncogene screening in multiple endocrine neoplasia type 2A (MEN2A).

METHODSComprehensive medical history was obtained for 5 members from a 3-generation family from southern China. Clinical investigations have included biochemical testing, imaging, and screening of germline RET proto-oncogene mutations.

RESULTSGenetic screening has revealed a missense mutation at codon 618(TGC>CGC) of exon 10 in 3 patients(p.C618R), which was consistent with their clinical manifestations. For the 3 individuals, the age at diagnosis was 21, 26 and 36 yr, and the maximum diameter of medullary thyroid carcinoma was 22, 25 and 39 cm, respectively. The 36-year-old female patient initially underwent right total thyroidectomy plus right neck lymph node dissection. Four years later, she again underwent left adrenal tumorectomy and left total thyroidectomy plus left neck lymph node dissection. The 21-year-old male patient underwent right total thyroidectomy plus right modified neck dissection. The follow-up was respectively 146 and 26 months following the initial operation. Two patients still presented elevated calcitonin and had bilateral neck lymph node masses and/or left thyroid masses on imaging examination. The 26-year-old female patient, who presented bilateral thyroid masses and elevated calcitonin, has refused thyroidectomy.

CONCLUSIONCombined family survey and RET gene screening can facilitate early diagnosis and surgical treatment to improve the prognosis.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Carcinoma, Neuroendocrine ; Exons ; Female ; Humans ; Male ; Molecular Sequence Data ; Multiple Endocrine Neoplasia Type 2a ; enzymology ; genetics ; Mutation, Missense ; Pedigree ; Proto-Oncogene Proteins c-ret ; genetics ; Thyroid Neoplasms ; enzymology ; genetics ; Young Adult

OBJECTIVE: To explore the pathological characteristics and significance of RET proto-oncogene screening in multiple endocrine neoplasia type 2A (MEN2A) with cutaneous lichen amyloidosis (CLA). METHODS: Clinical data of 51 members from 7 unrelated pedigrees of MEN2A-CLA were collected. Systemic clinical investigations including biochemical testing, imaging examination, germline RET variant screening and histopathological examination were carried out. RESULTS: RET gene variants were detected in 28 patients with MEN2A (C634G/F/R/S/W and C611Y) including 12 males and 16 females, with the mean age of diagnosis being (41.1 ± 18.3) years old, which were consistent with their clinical manifestations. The incidence of medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), hyperparathyroidism (HPTH) and CLA among 28 MEN2A patients were 89.3%, 28.6%, 7.1% and 28.6%, respectively. Comparison of the incidence of MTC/PHEO/HPTH and CLA between C611Y and C634G/F/R/S/W, only PHEO and CLA in C611Y were lower than those in C634G/F/R/S/W (P < 0.05; P < 0.05). Among 8 patients with CLA, the male to female ratio was 2 : 6. The clinical features included pruritus in the interscapular region and presence of dry, thickened, scaly, brown pigment, clustered or desquamate-like plaques. The mean onset age of CLA [(18.4 ± 4.6) years] versus the mean age at diagnosis of CLA or MEN2A were significantly different (P < 0.001; P < 0.001). CONCLUSION MEN2A-CLA may be the early clinical manifestation of MEN2A and most frequently occurred along with RET-C634 variant. To facilitate the recognition of MEN2A-CLA, to combine family investigation and screening of RET variant are helpful for early diagnosis and standardized treatment, which can improve the long-term outcome of MEN2A-specific tumors.
Adolescent ; Adrenal Gland Neoplasms ; Adult ; Amyloidosis, Familial ; Carcinoma, Neuroendocrine ; China ; Female ; Humans ; Lichens ; Male ; Middle Aged ; Multiple Endocrine Neoplasia Type 2a/genetics* ; Pheochromocytoma ; Proto-Oncogene Proteins c-ret/genetics* ; Skin Diseases, Genetic ; Thyroid Neoplasms/genetics* ; Young Adult

OBJECTIVETo investigate the clinical features and mutations of RET proto-oncogene in a pedigree affected with multiple endocrine neoplasia type 2A (MEN2A).

METHODSClinical data of the family members was collected. Genomic DNA from peripheral blood leukocytes were extracted and subjected to PCR amplification. Exons 8, 10, 11, 13, 14, 15, 16 of the RET gene was sequenced.

RESULTSA missense mutation p.C634W was detected in 8 members from the family. Among them, 3 were diagnosed with pheochromocytoma, 1 with medullary thyroid carcinoma, 1 with medullary thyroid carcinoma and pheochromocytoma, 1 with medullary thyroid carcinoma and hyperparathyroidism. One member was found with thyroid enlargement but refused further examination, and another one was identified as carrier of the RET gene mutation.

CONCLUSIONA p.C634W mutation has been detected in a family affected with MEN2A, in which most carriers have developed clinical symptoms. RET mutation detection should be routinely performed for families affected with MEN2A.

Adult ; Aged ; Base Sequence ; Carcinoma, Medullary ; genetics ; Carcinoma, Neuroendocrine ; genetics ; Child ; Child, Preschool ; Exons ; genetics ; Family Health ; Female ; Genetic Predisposition to Disease ; genetics ; Humans ; Male ; Middle Aged ; Multiple Endocrine Neoplasia Type 2a ; genetics ; Mutation, Missense ; Pedigree ; Pheochromocytoma ; genetics ; Proto-Oncogene Proteins c-ret ; genetics ; Sequence Analysis, DNA ; methods ; Thyroid Neoplasms ; genetics