IS THAT THE R171Q AMINO ACID VARIANT IN EXON 3 OF THE MEN1 GENE IS RELATED TO AGE, TO PLAY A MUTATING ROLE?

Background/aim: Several studies demonstrated that the R171Q amino acid variant in exon 3 of MEN1 gene is a polymorphism, and in some new studies it is probably a mutation. We found in our study of twelve cases, two young cases have this variant and developed multiple endocrine neoplasia type1. Materials and methods: twelve MEN1 young patients (7 female, 5 male) aged between 20 and 40 years old, were included in our study. After investigating each patient, biochemical and molecular researches is done. We sequenced exon 3 of the MEN1 gene of patients and some members of their families. Results: Ten patients have MEN1 syndrome and they have no mutation in MEN1 gene. Two patients from separated families have a c.512G>A heterozygote variant. Phenotypically the two cases have hyperparathyroidism in young age. One of them developed others tumors later. Conclusion: The R171Q variant is a mutation in some cases; causes hyperparathyroidism and will develop further MEN1 lesions later, and it is just a polymorphism in other cases. We believe that when this polymorphism combines with young age in severe depression, it will lead to MEN1 syndrome, which will make this polymorphism considered a genetic mutation

Open Medicine ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 424-430
Author(s):  
Audrius Šileikis ◽  
Edvinas Kildušis ◽  
Ramūnas Janavičius ◽  
Kęstutis Strupas

AbstractMultiple endocrine neoplasia syndrome, type 1 (MEN1) is an underdiagnosed autosomal dominant inherited cancer predisposition syndrome with inter- and intrafamilial variability without a known genotype-phenotype correlation. Disease is caused by mutations in the MEN1 gene located on chromosome 11, but other genes (CDKN1B, AIP) and mechanisms might be involved too. We performed retrospective case series study of MEN1 syndrome patient and his family and present our experience of management of genetically confirmed 9 MEN1 syndrome large family members from Lithuania with novel MEN1 gene mutation (MEN1 exon 6 — c. 879delT (p.Pro293Profs*76)) and delineate its clinical phenotype. At present the diagnosis of MEN1 syndrome must be established by direct mutation testing. MEN1 syndrome patients, their relatives and patients suspected of MEN1 are eligible for mutation testing. Patients with MEN1 have a shorter life expectancy than the general population. MEN1 patients and mutation carriers should be subjected to periodic screening in order to detect manifestations in an early stage. Early genetic diagnosis and subsequent periodic screening is associated with less morbidity and mortality at follow-up. Our study confirmed the absence of genotype-phenotype correlation and showed high intrafamilial clinical expression variability of the MEN1 syndrome.


2020 ◽  
Vol 1 (2) ◽  
pp. 1-13
Author(s):  
Anubha Bajaj

Multiple endocrine neoplasia type 1 (MEN1) is a syndrome emerging from characteristic mutations of MEN1 gene with concurrently enunciated multiple endocrine and tumours and associated non-endocrine neoplasm. Previously designated as Werner’s syndrome, MEN1 syndrome denominates genomic mutation within chromosome 11q13 or a tumour suppressor gene with a distinctive protein product nomenclated as “menin”. MEN1 syndrome demonstrates an autosomal dominant pattern of disease inheritance where genomic mutations delineate a comprehensive (100%) disease penetrance. MEN1 gene was initially identified in 1997 upon chromosome 11q13. Although twelve genetic mutations were primarily identified, currently beyond eighteen hundred genomic mutations are scripted1, 2. MEN1 syndrome is comprised of diverse combination of twenty or more endocrine and non-endocrine tumours exemplifying a classic triad of pituitary, parathyroid and pancreatic neoplasm. Diverse non endocrine tumours enunciated with MEN1 syndrome are denominated with meningioma, ependymoma or angiofibroma1, 2. Endocrine tumours are discerned on account of excessive hormonal secretion engendered from various neoplasm or on account of neoplastic evolution. Approximately 10% instances can occur due to a de-novo genomic variant. Offspring of an individual with MEN1 syndrome quantifies a 50% possibility of inheriting the genomic variant. Cogent prenatal diagnosis can be determined in instances where specific genomic variant of a particular family is known. Physical, psychological and social restrictions are prevalent with MEN1 syndrome. Heterozygotes with MEN1 genetic variant are denominated as carriers and manifest a two- fold possible mortality1, 2.


2021 ◽  
Vol 22 (14) ◽  
pp. 7352
Author(s):  
Francesca Marini ◽  
Maria Luisa Brandi

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant inherited multiple cancer syndrome of neuroendocrine tissues. Tumors are caused by an inherited germinal heterozygote inactivating mutation of the MEN1 tumor suppressor gene, followed by a somatic loss of heterozygosity (LOH) of the MEN1 gene in target neuroendocrine cells, mainly at parathyroids, pancreas islets, and anterior pituitary. Over 1,500 different germline and somatic mutations of the MEN1 gene have been identified, but the syndrome is completely missing a direct genotype-phenotype correlation, thus supporting the hypothesis that exogenous and endogenous factors, other than MEN1 specific mutation, are involved in MEN1 tumorigenesis and definition of individual clinical phenotype. Epigenetic factors, such as microRNAs (miRNAs), are strongly suspected to have a role in MEN1 tumor initiation and development. Recently, a direct autoregulatory network between miR-24, MEN1 mRNA, and menin was demonstrated in parathyroids and endocrine pancreas, showing a miR-24-induced silencing of menin expression that could have a key role in initiation of tumors in MEN1-target neuroendocrine cells. Here, we review the current knowledge on the post-transcriptional regulation of MEN1 and menin expression by miR-24, and its possible direct role in MEN1 syndrome, describing the possibility and the potential approaches to target and silence this miRNA, to permit the correct expression of the wild type menin, and thereby prevent the development of cancers in the target tissues.


1999 ◽  
pp. 475-480 ◽  
Author(s):  
N Hai ◽  
N Aoki ◽  
A Matsuda ◽  
T Mori ◽  
S Kosugi

OBJECTIVE: Multiple endocrine neoplasia type 1 (MEN1) is a syndrome of endocrine tumors involving the parathyroids, anterior pituitary and enteropancreatic neuroendocrine tissues, and is inherited in an autosomal dominant manner. Recently, the gene responsible for this syndrome, MEN1, was positionally cloned in 11q13. We aimed to assess the significance of MEN1 gene diagnostics in families with MEN1. DESIGN: Sixteen probands of familial MEN1 and their 40 family members were subjected to the study. METHODS: Full-length sequencing of the open reading frame and exon-intron boundaries in the MEN1 gene was performed with probands of familial MEN1. Family members were examined for the identified mutation in the proband. RESULTS: We identified heterozygous germline mutations of the MEN1 gene in all of 16 Japanese MEN1 families examined, achieving the highest detectability of MEN1 mutations in familial MEN1 among studies that examined more than 10 families. Eleven kinds of the identified MEN1 germline mutations were novel. More than half were nonsense or frameshift mutations resulting in a premature stop codon (9/15; 60%), and no mutation hot spots or no apparent genotype-phenotype relationships were observed, in support of the results of other studies. We identified 40 mutant MEN1 gene carriers and 16 non-carriers in the course of the present study in those families. CONCLUSIONS: Analysis of the germline mutations in the MEN1 gene, providing significantly useful clinical information to probands and family members of MEN1, should be considered as a standard procedure and categorized as belonging to Group 1 cancer predisposition testing by the American Society of Clinical Oncology.


2000 ◽  
Vol 166 (1) ◽  
pp. 1-9 ◽  
Author(s):  
W Karges ◽  
K Jostarndt ◽  
S Maier ◽  
A Flemming ◽  
M Weitz ◽  
...  

Germ line mutations of the multiple endocrine neoplasia type 1 (MEN1) tumour suppressor gene cause MEN1, a rare familial tumour syndrome associated with parathyroid hyperplasia, adenoma and hyperparathyroidism (HP). Here we investigated the role of the MEN1 gene in isolated sporadic and familial HP. Using RT-PCR single-strand conformational polymorphism screening, somatic (but not germ line) mutations of the MEN1 coding sequence were identified in 6 of 31 (19.3%) adenomas from patients with sporadic primary HP, but none in patients (n=16) with secondary HP due to chronic renal failure. MEN1 mutations were accompanied by a loss of heterozygosity (LOH) for the MEN1 locus on chromosome 11q13 in the adenomas as detected by microsatellite analysis. No DNA sequence divergence within the 5' region of the MEN1 gene, containing the putative MEN1 promoter, was detectable in HP adenomas. Clinical characteristics were not different in HP patients with or without MEN1 mutation. Heterozygous MEN1 gene polymorphisms were identified in 9.6% and 25% of patients with primary and secondary HP respectively. In a large kindred with familial isolated familial HP, MEN1 germ line mutation 249 del4 and LOH was associated with the HP phenotype and a predisposition to non-endocrine malignancies. We suggest that the bi-allelic somatic loss of MEN1 wild-type gene expression is involved in the pathogenesis of a clinically yet undefined subset of sporadic primary HP adenomas. MEN1 genotyping may further help define the familial hyperparathyroidism-MEN1 disease complex, but it seems dispensable in sporadic primary HP.


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