Diagnosis by Serendipity: Cushing Syndrome Attributable to Cortisol-Producing Adrenal Adenoma as the Initial Manifestation of Multiple Endocrine Neoplasia Type 1 Due to a Rare Splicing Site Men1 Gene Mutation

ObjectiveTo report a case that highlights the potential for Cushing syndrome to be the first manifestation of multiple endocrine neoplasia type 1 (MEN 1) syndrome and to describe the rare underlying genetic mutation and the heterogeneous manifestations of the syndrome within the same family.MethodsWe present a case report including biochemical and radiologic findings, review family data, and discuss the results of genetic analyses.ResultsA 16-year-old girl who was not known to have any medical illness and had no known family history of MEN 1 syndrome presented with Cushing syndrome attributable to a cortisol-producing adrenal adenoma. During her evaluation, she was found to have primary hyperparathyroidism and a pituitary microprolactinoma. These findings raised the possibility of MEN 1 syndrome. She did not have clinical, biochemical, or radiologic evidence of islet cell pancreatic tumors. Family screening showed that her father had evidence of primary hyperparathyroidism, mild hyperprolactinemia, normal findings on magnetic resonance imaging of the pituitary, and a 1.2- cm nodule in the tail of the pancreas in conjunction with slight elevation of serum insulin and normal gastrin levels. The patient’s 5 siblings had evidence of primary hyperparathyroidism, and 2 of them also had mild hyperprolactinemia. Genetic screening confirmed the presence of a MEN1 gene missense G to A mutation in the patient, her father, and her siblings at the splicing site of intron 6 (IVS6 + 1G > A). This mutation leads to frameshift and truncation of the MEN1 gene.ConclusionIn MEN 1, Cushing syndrome is an extremely rare and usually late manifestation. Most cases are due to corticotropin-producing pituitary adenomas. Although Cushing syndrome generally develops years after the more typical manifestations of MEN 1 appear, it may be the primary manifestation of MEN 1 syndrome. There is considerable heterogeneity in the manifestations of MEN 1, even within a family having the same genetic mutation. (Endocr Pract. 2008;14:595-602)     

The Importance of Periodical Screening for Primary Hyperparathyroidism in a Pituitary Tumor Cohort in Searching Patients With MEN1 and Its Genetic Profile

ObjectiveMultiple endocrine neoplasia type 1 (MEN1) is a rare genetic syndrome characterized by parathyroid, anterior pituitary, and/or duodenopancreatic neuroendocrine tumors. Studies have indicated that investigating primary hyperparathyroidism (pHPT) with subsequent genetic screening may be an essential tool for the early diagnosis of MEN1 in patients with pituitary tumors (PTs). This study aimed to investigate the presence of pHPT in patients with PTs and, subsequently, to screen for genetic mutations and related tumors in patients with MEN1 syndrome.MethodsThis study included 255 patients with PTs who were assessed for the presence of MEN1 by serum calcium and parathyroid hormone measurements. Mutation screening of the MEN1, CDKN1B, and AIP genes was performed in the index cases showing the MEN1 phenotype.ResultsFive patients with PTs presented a clinical condition compatible with MEN1. These patients had a younger age of onset and a more severe clinical condition. Genetic analysis identified a frameshift mutation in the MEN1 gene in one of the cases with the MEN1 phenotype, but point mutations in CDKN1B and AIP were not detected in any of these patients.ConclusionOur results show that periodic screening for pHPT in patients with PTs may be useful to detect MEN1 syndrome; thus, it is recommended in those patients with both findings a genetic analysis of MEN1 gene and an additional search of related tumors. By contrast, our data suggest that CDKN1B and AIP mutations do not seem to play a relevant role in the pathogenesis of MEN1.     

Mutation and Expression of Gene YY1 in Pancreatic Neuroendocrine Tumors and Its Clinical Significance

ObjectiveThe clinical significance of the YY1 gene mutation and expression in pancreatic neuroendocrine tumors (PNETs) remains unknown. Therefore, this study aimed to comprehensively analyze the somatic mutation of YY1 in the different subtypes of PNETs.MethodsA total of 143 PNETs were assessed by Sanger sequencing to identify the somatic mutation of YY1 gene in various subtypes of PNETs. YY1 protein expression was examined in 103 PNETs by immunohistochemical staining and western blot. Gene mutation and its protein expression were correlated with clinicopathologic features.ResultsA recurrent mutation (chr14:100743807C>G) in the YY1 gene was identified in 15 of 83 insulinomas (18%) and in only 1 of 60 noninsulinoma PNETs (1.7%) (P = .0045). The YY1 mutation was not found in MEN1-associated insulinomas. The YY1 mutation in insulinomas was correlated with older age and lower serum glucose levels (age, 57 vs 42.5 years, P = .006; blood glucose, 25.2 vs 33.6 mg/dL, P = .008). YY1 protein expression was found in 100 of 103 PNETs, although expression was weaker in metastases than in localized tumors (P = .036). The stronger expression of YY1 protein was associated with favorable disease-free survival of patients with PNETs (log-rank, P = .011; n = 70). Multivariable statistical analysis showed that YY1 protein expression could be an independent predictor of prognosis.ConclusionThe hotspot YY1 mutation mostly occurred in insulinomas and rarely in noninsulinoma PNETs. The stronger YY1 protein expression was correlated with the better prognosis of PNETs patients.     

Mutation analysis of EXT1 and EXT2 Genes in a Korean family with multiple exostoses

A 35-year-old female patient diagnosed clinically as multiple exostosis visited the hospital for infertility evaluation and treatment. She had an operation in pelvis, humerus, tibia and femur in 1993. An extended pedigree analysis showed three of her siblings and several cousins have suffered from the same disease with a typical autosomal dominant pattern of inheritance. So she wanted a genetic test for her disease before having a child. For mutation analysis, DNAs were extracted from the patient and her brother. All exons and exon-intron boundaries of EXT1 and EXT2 genes were amplified by polymerase chain reactions. The PCR products were directly sequenced and analyzed by ABI genetic analyzer. A single base pair deletion c.2241delC in the exon 6 of EXT1 gene was detected in both patient and her brother. Generation of a premature stop codon resulting from frameshift of codons might be a causative of the disease. According to the human genome mutation data base (HGMD), the mutation detected is not previously documented.     

Parathyroid Carcinoma in Multiple Endocrine Neoplasia Type 1 with a Classic Germline Mutation

ObjectiveTo report the case of a patient with multiple endocrine neoplasia type 1 (MEN 1) syndrome with concomitant parathyroid carcinoma and a classic MEN1 germline mutation.MethodsWe present the clinical findings, laboratory results, imaging studies, and surgical histopathologic features in a woman with MEN 1 syndrome and concomitant parathyroid carcinoma. We also review the literature regarding patients with similar clinical entities and the use of adjuvant radiotherapy for parathyroid carcinoma.ResultsA 53-year-old woman presented with nausea and severe primary hyperparathyroidism. Computed tomography revealed parathyroid masses, shown later to be bilateral parathyroid carcinomas and adenomas. Magnetic resonance imaging demonstrated a pituitary macroadenoma, and gastrinomas were confirmed by computed tomography and a secretin stimulation test. She was successfully treated with total thyroidectomy, subtotal parathyroidectomy, and adjuvant radiotherapy. Genetic analysis revealed a classic MEN1 germline mutation.ConclusionThis report describes a patient with parathyroid carcinoma occurring in conjunction with MEN 1, further characterizing this rare condition. In contrast to previously described patients, our patient is the first with a classic MEN1 germline mutation, confirming that parathyroid cancer can occur in association with classic MEN 1 genetics. (Endocr Pract. 2009;15:567-572)     

Cushing Syndrome Secondary to A Thymic Carcinoid Tumor Due to Multiple Endocrine Neoplasia Type 1

ObjectiveTo present an Iranian patient with a nonclassic form of multiple endocrine neoplasia type 1 (MEN 1) who presented with ectopic Cushing syndrome (CS) secondary to a corticotropin (ACTH)-producing thymic neuroendocrine tumor (NET), recurrent renal stones, and a giant cell granuloma of the jaw due to primary hyperparathyroidism (PHPT) without involvement of the pituitary or pancreas.MethodsRelevant imaging and hormonal evaluations were performed. The patient was operated on 2 occasions for a thymic NET and on 3 occasions for PHPT. DNA from a peripheral blood sample was extracted for sequencing of the MEN1 gene.ResultHistopathologic evaluation of the thymic tumor removed during the first surgery showed an atypical carcinoid tumor with a Ki-67 labeling index of 5%. Evaluation after the second surgery revealed an invasive carcinoid tumor with a Ki-67 labeling index of 30%.Parathyroid pathology was suggestive of glandular hyperplasia. Menin gene sequencing revealed a novel frameshift mutation c.1642_1648dup in exon 10.ConclusionThis case of MEN 1 is unusual because most thymic NETs in MEN 1 are nonfunctional, and secretion of ACTH or other ectopic hormones rarely occurs. In patients presenting with thymic NETs, the possibility of MEN 1 should be considered, especially in the presence of hyperparathyroidism. This case also demonstrates that the behavior of thymic NETs can change over time from slow-growing tumors to highly invasive neoplasia, and that ectopic ACTH can be produced by these tumors in the context of MEN 1. (Endocr Pract. 2011;17:e92-e96)     

Novel deletion mutation of TRPS1 gene in a Chinese patient of trichorhinophalangeal syndrome type I

Tricho–rhino–phalangeal syndrome (TRPS) is a rare autosomal dominant disorder. Deletion or mutation of the TRPS1 gene leads to the tricho–rhino–phalangeal syndromes type I or type III. In this article, we describe a Chinese patient affected with type I TRPS and showing prominent pilar, rhinal and phalangeal abnormalities. Mutational screening and sequence analysis of TRPS1 gene revealed a previously unidentified four-base-pair deletion of nucleotides 1783–1786 (c.1783_1786delACTT). The mutation causes a frame shift after codon 593, introducing a premature stop codon after 637 residues in the gene sequence. This deletion is an unquestionable loss-of-function mutation, deleting all the functionally important parts of the protein. Our novel discovery indicates that sparse hair and metacarpal defects of tricho–rhino–phalangeal syndromes in this patient are due to this TRPS1 mutation. And this data further supports the critical role of TRPS1 gene in hair and partial skeleton morphogenesis.     

Unusual Case of Multiple Endocrine Neoplasia Type 2A Syndrome Without Medullary Thyroid Carcinoma

ObjectiveTo present an unusual case of multiple endocrine neoplasia type 2A (MEN 2A) syndrome and to describe how this case differs from the typical clinical features and usual genetic variations seen in classic MEN 2A syndrome.MethodsWe describe the work-up, diagnosis, and treatment course of a patient who presented with multifocal pheochromocytomas, parathyroid adenoma, thyroid abnormalities, and a RET mutation.ResultsA 65-year-old man with previously treated pheochromocytoma presented with a parathyroid adenoma, multiple thyroid nodules, and a RET polymorphism. C-cell hyperplasia (CCH) or medullary thyroid carcinoma (MTC) occurs with nearly 100% penetrance in patients with MEN 2A syndrome. Our patient did not have CCH or frank MTC, but he expressed the other manifestations of the MEN 2A syndrome.ConclusionMEN 2A syndrome is characterized by the occurrence of MTC, pheochromocytomas, and parathyroid hyperplasia or adenomas. It is inherited in an autosomal dominant fashion, and more than 80% of patients with MEN 2A have a specific substitution on codon 634 of the RET proto-oncogene. Despite the nearly 100% penetrance of MTC or CCH in patients with MEN 2A, our patient did not have this. Additionally, he exhibited a RET mutation that is uncommonly seen in classic MEN 2A syndrome. Our patient may have a MEN 2A variant or a pseudo-MEN 2A syndrome. (Endocr Pract. 2011;17:e4-e7)     

Two Novel Mutations on Exon 8 and Intron 65 of COL7A1 Gene in Two Chinese Brothers Result in Recessive Dystrophic Epidermolysis Bullosa

Dystrophic epidermolysis bullosa is an inherited bullous dermatosis caused by the COL7A1 gene mutation in autosomal dominant or recessive mode. COL7A1 gene encodes type VII collagen – the main component of the anchoring fibrils at the dermal–epidermal junction. Besides the 730 mutations reported, we identified two novel COL7A1 gene mutations in a Chinese family, which caused recessive dystrophic epidermolysis bullosa (RDEB). The diagnosis was established histopathologically and ultrastructurally. After genomic DNA extraction from the peripheral blood sample of all subjects (5 pedigree members and 136 unrelated control individuals), COL7A1 gene screening was performed by polymerase chain reaction amplification and direct DNA sequencing of the whole coding exons and flanking intronic regions. Genetic analysis of the COL7A1 gene in affected individuals revealed compound heterozygotes with identical novel mutations. The maternal mutation is a 2-bp deletion at exon 8 (c.1006_1007delCA), leading to a subsequent reading frame-shift and producing a premature termination codon located 48 amino acids downstream in exon 9 (p.Q336EfsX48), consequently resulting in the truncation of 2561 amino acids downstream. This was only present in two affected brothers, but not in the other unaffected family members. The paternal mutation is a 1-bp deletion occurring at the first base of intron 65 (c.IVS5568+1delG) that deductively changes the strongly conserved GT dinucleotide at the 5′ donor splice site, results in subsequent reading-through into intron 65, and creates a stop codon immediately following the amino acids encoded by exon 65 (GTAA→TAA). This is predicted to produce a truncated protein lacking of 1089 C-terminal amino acids downstream. The latter mutation was found in all family members except one of the two unaffected sisters. Both mutations were observed concurrently only in the two affected brothers. Neither mutation was discovered in 136 unrelated Chinese control individuals. This study reveals novel disease-causing mutations in the COL7A1 gene.     

Mody-3: Novel HNF1A Mutation and the Utility of Glucagon-Like Peptide (GLP)-1 Receptor Agonist Therapy

ObjectiveAn estimated 1 to 2% of cases of diabetes mellitus have a monogenic basis; however, delayed diagnosis and misdiagnosis as type 1 and 2 diabetes are common. Correctly identifying the molecular basis of an individual’s diabetes may significantly alter the management approach to both the patient and his or her relatives. We describe a case of mature onset diabetes of the young (MODY) with sufficient evidence to support the classification of a novel HNF1A (hepatocyte nuclear factor-1-α) mutation as a cause of MODY-3.MethodsA 21-year-old Caucasian female presented to our office with a diagnosis of noninsulin-dependent diabetes mellitus (NIDDM) at age 10; glycemia was initially managed with oral antidiabetic (OAD) agents and insulin detemir. The patient reported a strong family history of early-onset NIDDM in both her mother and maternal grandmother, both of whom eventually required insulin therapy to control glycemia. The patient’s medical and family history were highly suggestive of maturity-onset diabetes of the young (MODY), and genetic testing was performed.ResultsGenetic screening detected a mutation p.Arg200Trp in the HNF1A gene in the patient, her mother, and maternal grandmother, suggesting a diagnosis of MODY-3. This finding resulted in a change of antidiabetic therapy in all 3 patients, including the addition of once-daily liraglutide therapy, which helped improve their glycemic control.ConclusionOur case report supports the classification of the p.Arg200Trp mutation as a cause of MODY-3. The findings also suggest that glucagon-like peptide-1 (GLP-1) receptor agonist therapy may be of value in managing glycemia in patients with MODY-3. (Endocr Pract. 2014;20:107-111)     

A Patient with an Apparently Sporadic Pheochromocytoma with a Rearranged During Transfection Codon 635 Variant: A Mild Form of Multiple Endocrine Neoplasia Type 2?

ObjectiveMultiple endocrine neoplasia 2 (MEN2) is an autosomal dominant disorder characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism, with mutations at codon 634 in exon 11 of the RET (REarranged during Transfection) proto-oncogene identified as the most common genetic defect.MethodsWe present a patient diagnosed with a left adrenal pheochromocytoma at a young age in whom we identified a mutation at codon 635 of the RET gene. No MTC has been clinically detected during a 6-year follow-up.ResultsThe C-to-T point mutation at nucleotide c.1903 results in an additional cysteine in the cysteine-rich domain due to the replacement of arginine with cysteine. One of the patient’s 2 children has the same sequence variant in the RET proto-oncogene and has remained unaffected during follow-up.ConclusionsThe majority of mutations in this disorder affect cysteine residues in the cysteine-rich region of the extracellular domain of the RET protein, disrupting normal cysteine pairing. Consequently, we consider that this variant is likely of pathogenic significance, but this has not been unequivocally confirmed. (Endocr Pract. 2014;20:e65-e68)     

A novel RLBP1 gene geographical area-related mutation present in a young patient with retinitis punctata albescens

Background

Autosomal recessive forms of retinitis punctata albescens (RPA) have been described. RPA is characterized by progressive retinal degeneration due to alteration in visual cycle and consequent deposit of photopigments in retinal pigment epithelium. Five loci have been linked to RPA onset. Among these, the retinaldehyde-binding protein 1 gene, RLBP1, is the most frequently involved and several founder mutations were reported. We report results of a genetic molecular investigation performed on a large Sicilian family in which appears a young woman with RPA.

Results

The proband is in homozygous condition for a novel RLBP1 single-pair deletion, and her healthy parents, both heterozygous, are not consanguineous. Thenovelc.398delC (p.P133Qfs*258) involves the exon 6 and leads to a premature stop codon, resulting in a truncated protein entirely missing of CRAL-TRIO lipid-binding domain.Pedigree analysis showed other non-consanguineous relatives heterozygous for the same mutation in the family. Extension of mutation research in the native town of the proband revealed its presence also in healthy subjects, in a heterozygous condition.

Conclusions

A novel RLBP1 truncating mutation was detected in a young girl affected by RPA. Although her parents are not consanguineous, the mutation was observed in a homozygous condition. Being them native of the same small Sicilian town of Fiumedinisi, the hypothesis of a geographical area-related mutation was assessed and confirmed.

     

Whole Genome Sequencing Reveals a De Novo SHANK3 Mutation in Familial Autism Spectrum Disorder

IntroductionClinical genomics promise to be especially suitable for the study of etiologically heterogeneous conditions such as Autism Spectrum Disorder (ASD). Here we present three siblings with ASD where we evaluated the usefulness of Whole Genome Sequencing (WGS) for the diagnostic approach to ASD.MethodsWe identified a family segregating ASD in three siblings with an unidentified cause. We performed WGS in the three probands and used a state-of-the-art comprehensive bioinformatic analysis pipeline and prioritized the identified variants located in genes likely to be related to ASD. We validated the finding by Sanger sequencing in the probands and their parents.ResultsThree male siblings presented a syndrome characterized by severe intellectual disability, absence of language, autism spectrum symptoms and epilepsy with negative family history for mental retardation, language disorders, ASD or other psychiatric disorders. We found germline mosaicism for a heterozygous deletion of a cytosine in the exon 21 of the SHANK3 gene, resulting in a missense sequence of 5 codons followed by a premature stop codon ({"type":"entrez-nucleotide","attrs":{"text":"NM_033517","term_id":"380748962","term_text":"NM_033517"}}NM_033517:c.3259_3259delC, p.Ser1088Profs*6).ConclusionsWe reported an infrequent form of familial ASD where WGS proved useful in the clinic. We identified a mutation in SHANK3 that underscores its relevance in Autism Spectrum Disorder.     

Ectopic Acromegaly due to A Pancreatic Neuroendocrine Tumor Producing Growth Hormone-Releasing Hormone

ObjectiveTo present a case of acromegaly due to ectopic growth hormone-releasing hormone (GHRH) secretion from a pancreatic neuroendocrine tumor in the context of multiple endocrine neoplasia type 1 (MEN 1).MethodsWe describe the clinical, imaging, and pathologic findings of the study patient.ResultsA 46 year old woman presented with clinical and biochemical findings diagnostic of acromegaly. Magnetic resonance imaging showed a 1.2-cm sellar mass. Following resection of the macroadenoma, serum insulinlike growth factor 1 (IGF-1) and growth hormone (GH) levels remained unchanged. Pathologic examination revealed adenomatous changes, including a nonsecretory focus and a prolactin immunopositive area (GH stain negative in both). Octreotide long-acting release was ineffective. Search for an ectopic tumor included normal octreoscan and abdominal computed tomography. GHRH was greater than 1000 pg/mL. Repeated abdominal computed tomography documented a 6.2-cm mass in the tail and body of the pancreas. Distal pancreatectomy revealed a pancreatic neuroendocrine tumor that stained positive for GHRH. Postoperatively, serum GHRH and IGF-1 normalized. Re-evaluation of the initial pituitary pathologic specimen revealed additional somatotroph hyperplasia of the adjacent, normal pituitary gland. Primary hyperparathyroidism was diagnosed, and multigland parathyroid hyperplasia was noted at surgery. Genetic testing was positive for a mutation in the MEN1 gene.ConclusionThis patient’s acromegaly was resistant to somatostatin analogue therapy, reflecting the negative octreoscan imaging. In addition, this case is novel because the patient presented with pituitary adenomatous changes, which were presumably associated with MEN 1 and/or possibly the elevated GHRH levels. (Endocr Pract. 2011; 17:79-84)     

Recurrent Hyperparathyroidism and a Novel Nonsense Mutation in a Patient with Hyperparathyriodism-Jaw Tumor Syndrome

ObjectiveTo present the case of a hyperparathyroidism-jaw tumor (HPT-JT) patient with a novel nonsense mutation of the CDC73 gene.MethodsWe present the case of a patient with a history of three prior maxillectomies and two prior parathyroidectomies who presented with recurrent primary hyperparathyroidism (PHPT). We also briefly review the literature pertaining to HPT-JT.ResultsGenetic analysis revealed a novel nonsense mutation (c.85G>T; pGlu29) in exon 1 of CDC73. The patient’s son underwent genetic testing for a CDC73 mutation and was found to be negative.ConclusionHPT-JT is a rare condition characterized by PHPT and benign tumors of the mandible and maxilla. Up to 15% of HPT-JT patients with PHPT have parathyroid carcinoma. HPT-JT is associated with an inactivating mutation of CDC73, a gene that codes for the tumor suppressor protein parafibromin. This report expands our understanding of the genetics underlying this rare disorder and emphasizes the importance of early detection in order to prevent hypercalcemic complications such as parathyroid carcinoma. (Endocr. Pract. 2013;19:e134-e137)