McCune-Albright Syndrome with Acromegaly and Fibrous Dysplasia Associated with the GNAS Gene Mutation Identified by Sensitive PNA-clamping Method

Imanaka, Mari; Iida, Keiji; Nishizawa, Hitoshi; Fukuoka, Hidenori; Takeno, Ryoko; Takahashi, Kentaro; Kaji, Hiroshi; Takahashi, Yutaka; Okimura, Yasuhiko; Kaji, Hidesuke; Imanishi, Yasuo; Chihara, Kazuo

doi:10.2169/internalmedicine.46.0048

Cited by 18 publications

(20 citation statements)

References 10 publications

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“…The approximate frequency of these mutations was comparable to published data. [2][3][4][5][6][7][8][9][13][14][15][16][17][18][19] Twelve of 24 fibrous dysplasia cases were further tested by a general sequencing method. Ten of 12 cases of mutation detected by pyrosequencing assay were confirmed with general sequencing.…”

Section: Resultsmentioning

confidence: 99%

“…To increase the detection sensitivity of mutant species, a wild-type blocker such as peptide nucleic acid (PNA) clamping was used during PCR steps. This technique was first published by Bianco et al 18 and later adopted by other groups 8,19 to enable the detection when the mutant contents are below the analytical sensitivity. But this technique is not meant to measure the true percentage of mutant species in the lesion.…”

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confidence: 99%

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Quantitative Analysis of Activating Alpha Subunit of the G Protein (Gsα) Mutation by Pyrosequencing in Fibrous Dysplasia and Other Bone Lesions

Liang

Wei

Hodge

et al. 2011

The Journal of Molecular Diagnostics

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Benign fibro-osseous lesions (BFOLs) frequently display overlapping histological features. The differentiation of fibrous dysplasia (FD) from other BFOLs can be difficult, even for experienced orthopedic pathologists. Accurately distinguishing FD from other BFOLs may have significant clinical and treatment implications. A somatic mutation in gene GNAS encoding the ␣ subunit of the G protein (Gs␣) involving the codon corresponding to Arg 201 has been identified in FD and is specifically absent in other BFOLs. We have developed a quantitative assay by pyrosequencing that has a detection sensitivity of 95%. The test allows the identification of the two most common types of mutation (Arg¡His and Arg¡Cys) in a single reaction, with the ability to analyze other rare mutations. Of the 24 FD cases in this series, 23 (96%) were positive for GNAS/Gs␣ mutation. Nineteen of 23 positive cases exhibited a G¡A mutation (Arg¡His), whereas four had a C¡T mutation (Arg¡Cys). One of three BFOL, not otherwise specified cases was positive for G¡A mutation. None of the osteofibrous dysplasia, ossifying fibromas, or other bone lesions were positive for this mutation. Our experience is that pyrosequencing is an easy and accurate quantification method for Gs␣ mutation detection in fibrous dysplasia. Mutation analysis of the Gs␣ by pyrosequencing has significant potential for improving discrimination between FD and other BFOLs in problematic cases. Fibrous dysplasia is a benign fibro-osseous lesion (BFOL) of the medullary cavity, which may involve one or more bones.1 Because fibrous dysplasia (FD) and other BFOLs frequently display overlapping histological features, differentiation of FD from a BFOL can be difficult, even for experienced orthopedic pathologists, particularly on small biopsy samples.2,3 A somatic mutation at codon 201 of the ␣ subunit of G protein (Gs␣), encoded by the GNAS gene, has been identified in FD (monostotic and polyostotic forms) and in multiple endocrinopathies of McCune-Albright syndrome, 4 but is specifically absent in other BFOLs, such as osteofibrous dysplasia.3,5,6 Point mutations result in replacement of Arg (CGT) at position 201 with, most commonly, His (CAT) or Cys (TGT) 4 ; and in rare cases, with Ser (AGT), 7 Leu (CTT), 8 or Gly (GGT). 9The mutated Gs␣ is constitutively activated, leading to cAMP activation and downstream physiological responses in affected tissues, including bone, skin, endocrine glands, and other tissues. 4,10,11 Because of the mosaic nature of this mutation, the distribution of mutant cells and the ratio of mutant to normal cells in a lesion or affected individual may be reflected in the severity of phenotypic expression.10,11 Interestingly, the percentage of mutant stem cells decreases as a lesion ages resulting in "normalization" of FD of bone.12 Addressing these issues require an extremely sensitive and accurate quantitative assay for Arg201 mutation detection.Many detection assays have been developed to identify the Arg201 mutations. The two most widely used methods are direct ...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Quantitative Analysis of Activating Alpha Subunit of the G Protein (Gsα) Mutation by Pyrosequencing in Fibrous Dysplasia and Other Bone Lesions

Liang

Wei

Hodge

et al. 2011

The Journal of Molecular Diagnostics

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“…For example, patients with McCuneAlbright syndrome harbour germline GNAS mutations and present with a characteristic compendium of findings, including acromegaly, fibrous dysplasia and café au lait discoloration. [32][33][34] Approximately 40% of pituitary somatotroph (growth hormone secreting) adenomas demonstrate GNAS mutations at either codon 201 or codon 227. 35 GNAS mutations are uncommon in epithelial malignancies, occurring only in minor subsets of colorectal, prostate and breast cancers, renal cell carcinomas and small cell carcinomas of the lung, and these mutations are almost always restricted to codon 201.…”

Section: Discussionmentioning

confidence: 99%

GNAS Codon 201 mutations are uncommon in Intraductal Papillary Neoplasms of the Bile Duct

Matthaei¹,

Wu²,

Molin³

et al. 2012

Z Gastroenterol

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Abstracth pb_504 677..683Background: Activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. Intraductal papillary neoplasms of the bile ducts (IPNBs) morphologically resemble pancreatic IPMNs. This study sought to assess the mutational status of GNAS at codon 201 in IPNBs.Methods: Thirty-four patients were included. DNA from microdissected IPNBs was subjected to a polymerase chain reaction and ligation method for the detection of GNAS mutations at codon 201 and of KRAS mutations at codon 12. Mutational status was compared with clinical and pathologic data.Results: The IPNBs had a median diameter of 3.5 cm and were located intrahepatically (n = 6), extrahepatically (n = 13), both intra-and extrahepatically (n = 4) or in the gallbladder (intracystic papillary neoplasms, n = 11). Most exhibited pancreatobiliary differentiation (n = 20), high-grade dysplasia (n = 26) and an associated adenocarcinoma (n = 20). Analysis of GNAS codon 201 identified only one mutant sample in a multifocal intestinal subtype intrahepatic IPNB with high-grade dysplasia. Six lesions harboured a KRAS codon 12 mutation. Conclusions: GNAS codon 201 mutations are uncommon in IPNBs, by contrast with pancreatic IPMNs.More comprehensive molecular profiling is needed to uncover the pathways involved in IPNB development.

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“…Osteoblasts affected by the somatic GNAS mutation overexpress FGF23, which contributes to the pathology in fibrous dysplasia of bone. 22,23 Bone healing represents an accelerated repetition of endochondral and/or membranous bone formation. The preferred way of healing depends on the stability of the fractured site.…”

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FGF23 is a putative marker for bone healing and regeneration

Goebel¹,

Lienau

Rammoser³

et al. 2009

Journal Orthopaedic Research

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Besides numerous other factors, fibroblast growth factor receptor (FGFR) signaling is involved in fracture healing and bone remodeling. FGF23 is a phosphatonin produced by osteoblastic cells, which signals via FGFR1, thereby exerting effects in bone and kidney. We analyzed if serum FGF23 levels might be an indicator to predict fracture healing and union. FGF23 (C-Term) was elevated on day 3 postoperatively in 55 patients sustaining an exchange of total hip implants due to aseptic loosening. A prospective study of 40 patients undergoing primary hip arthroplasty also showed elevated FGF23 (C-Term) but no change in FGF23 (intact) levels on days 1, 4, and 10 postoperatively. Serum phosphate and phosphate clearance stayed within normal ranges. FGF23 mRNA expression in ovine callus was compared between a standard and delayed course of osteotomy healing. In the standard model, a marked increase in FGF23 mRNA expression compared to the delayed healing situation was observed. Immunohistochemical analysis showed FGF23 production of osteoblasts and granulation tissue in the fracture callus during bone healing. In conclusion, FGF23 is involved in bone healing, can be measured by a sensitive assay in peripheral blood, and is a promising candidate as an indicator for healing processes prone to reunion versus nonunion. Keywords: fibroblast growth factor 23; fracture healing; phosphate; arthroplasty Fibroblast growth factor 23 (FGF23) is a FGF family member that is expressed mainly in osteocytes. In pathophysiological conditions such as fibrous dysplasia osteoblasts and preosteoblasts are reported to produce FGF23. 1 The expression of FGF23 in chondrocytes, osteoclasts, and pericytes has also been shown.2 FGF23 signals are mediated via the FGF receptor 1(IIIc): the combined binding of FGF23 and the antiageing hormone Klotho has been shown to convert FGFR1 to an FGF23-specific receptor.3-7 FGF23 was originally identified and cloned as a causative factor for tumor induced osteomalacia (TIO), where mostly benign tumors overexpress phosphaturic factors such as FGF23, which causes renal phosphate wasting. [8][9][10] High FGF23 concentrations are associated with impaired 1a-hydroxylase activity in the kidney, leading to low 1,25(OH)2 vitamin D3 levels. [11][12][13] Additionally, the expression of the renal sodium phosphate transporters Npt1, Npt2a, and NPT2c is down-regulated by FGF23, thereby influencing the systemic regulation of phosphate metabolism.14,15 The FGF23 gene is linked to several inheritable syndromes such as autosomal dominant hypophosphatemic rickets (ADHR, gain of function mutations) and tumoral calcinosis (TC, loss of function mutations). ADHR results from a lack in protein processing by subtilisin-like-proteases due to a mutated RXXR cleavage motif within the protein structure. [16][17][18] TC is caused by either a mutation in GALNT3, a glycosyltransferase responsible for FGF23 glycosylation, or a mutation in a highly conserved FGF23 region resulting in decreased secretion. [19][20][21] Besides its functi...

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McCune-Albright Syndrome with Acromegaly and Fibrous Dysplasia Associated with the GNAS Gene Mutation Identified by Sensitive PNA-clamping Method

Abstract: Abstract

Cited by 18 publications

References 10 publications

Quantitative Analysis of Activating Alpha Subunit of the G Protein (Gsα) Mutation by Pyrosequencing in Fibrous Dysplasia and Other Bone Lesions

Quantitative Analysis of Activating Alpha Subunit of the G Protein (Gsα) Mutation by Pyrosequencing in Fibrous Dysplasia and Other Bone Lesions

GNAS Codon 201 mutations are uncommon in Intraductal Papillary Neoplasms of the Bile Duct

FGF23 is a putative marker for bone healing and regeneration

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