LncRNA GNAS-AS1 participates in the proliferation and migration of gastric cancer cells by regulating the miR-449a/Notch1 axis / 实用医学杂志

Objective To explore the impacts of long non-coding RNA(LncRNA)GNAS antisense RNA1(GNAS-AS1)on the proliferation and migration of gastric cancer(GC)cells by regulating the miR-449a/Notch1 axis.Method Tumor tissue and adjacent tissue samples were collected from 30 patients diagnosed with GC at Sichuan Provincial People's Hospital from September 2013 to September 2017;GC cells AGS were randomly divided into Control group,si-NC group,si-GNAS-AS1 group,si-GNAS-AS1+inhibitor NC group,and si-GNAS-AS1+miR-449a inhibitor group.Real-time fluorescence quantitative PCR method was applied to detect the expres-sion of GNAS-AS1,miR-449a,and Notch1 mRNA;MTT experiments and plate cloning experiments were applied to detect the proliferation;wound healing test was applied to detect cell migration;Transwell experiment was applied to detect cell invasion.Western Blot was applied to detect the expression of Notch1,E-cadherin,Vimentin,and N-cadherin proteins.Double Luciferase reporter gene experiment was applied to verify the relationship between GNAS-AS1 and miR-449a,between miR-449a and Notch1,respectively.Results Compared with adjacent tissues,the expression of GNAS-AS1 and Notch1 mRNA in tumor tissue was increased,the expression of miR-449a was reduced(P<0.05).Compared with the Control group and si-NC group,the expression of GNAS-AS1,OD490 value,number of clones formed,scratch healing rate,number of cell invasions,and the expression of Notch1,Vimentin,and N-cadherin proteins in AGS cells in the si-GNAS-AS1 group reduced,the expression of miR-449a and E-cadherin protein increased(P<0.05).Compared with the si-GNAS-AS1 group and the si-GNAS-AS1+inhibitor NC group,the OD490 value,scratch healing rate,number of cell invasions,Notch1,Vimentin,and N-cadherin expression in the si-GNAS-AS1+miR-449a inhibitor group increased,the expression of miR-449a and E-cadherin protein reduced(P<0.05).GNAS-AS1 targeted and negatively regulated miR-449a expression,while miR-449a targeted and negatively regulated Notch1 expression.Conclusion Silencing GNAS-AS1 may inhibit the expression of Notch1 protein by up-regulating miR-449a,thereby inhibiting the proliferation,migration,and invasion pro-cesses of GC cells.

PTBP1 Promotes Growth, Migration and Invasion of Cholangiocarcinoma Cells by Regulating mRNA Alternative Splicing / 中国生物化学与分子生物学报

Cholangiocarcinoma (CCA) is a highly invasive type of cancer with insidious onset and high mortality. Polypyrimidine tract-binding protein 1 (PTBP1) is highly over-expressed in various types of tumor tissues, which contributes to cancer progression. But the role of PTBP1 in CCA has not been explored yet. In this study, we aim to investigate the function of PTBP1 in CCA. Therefore, we used publicly available data from the cancer genome atlas (TCGA) to evaluate the dysregulation of PTBP1 in CCA. The results showed that the PTBP1 is significantly up-regulated in CCA tissues compared to the matched non-tumor tissues (P < 0. 05). We assessed the effects of PTBP1 on the growth of CCA cell lines RBE and HuH28 by performing CCK-8 and plate colony formation assays. The results showed that overexpression of PTBP1 significantly promoted the growth (P < 0. 01) of CCA cells, whereas knockdown of PTBP1 exhibited opposite effects. Transwell and Invasion assays revealed that overexpression of PTBP1 significantly promotes the migration and invasion of CCA cells (P < 0. 001), whereas knockdown of PTBP1 exhibited opposite effects (P < 0. 001). The RNA sequencing (RNA-seq) analysis in PTBP1-depleted cells showed that the up-regulated genes are significantly enriched in p53 signaling pathway, while the down-regulated genes are represented by cholesterol metabolism, Rho GTPase and TGF-β pathways. Then, the alternative splicing analysis revealed that inhibition of PTBP1 led to series of aberrant alternative splicing events, including several cancer-associated ones, such as splicing events within the TGF-β regulator TGIF1 and the p53 activity-correlated gene GNAS. These results indicate that PTBP1 promotes the progression of CCA likely by regulating the transcriptome alternative splicing to influence multiple cancer-associated signaling pathways.

G protein gene variants in schizophrenia

Abstract Background Various studies demonstrating enhanced vulnerability to apoptosis may contribute to the pathobiology of schizophrenia. Objective Thus, G proteins may provide an intriguing link between the signal transduction, and apoptotic hypotheses of schizophrenia. In the light of these findings, we investigated whether G protein gene polymorphisms (GNAS1-T393C and GNB3-C825T) accounted for an increased risk of schizophrenia. Methods The present analyses were based on 100 subjects diagnosed with schizophrenia, and on 100 unrelated healthy controls. The genotyping of GNAS1-T393C, and GNB3-C825T gene polymorphisms were performed using the polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Results: We demonstrated the positive association of GNB3-C825T gene variants with schizophrenia risk (p: 0.023). In our study, more prevalent CC genotype frequencies were detected in GNB3 in patients compared with the frequencies in the controls. The individuals with GNB3-C825T CC genotype had 2 fold increased risk for schizophrenia (p: 0.011, c2: 6.39, OR:2.14, 95% CI: 1.18-3.90). Discussion Our study results suggested that GNB3-C825T polymorphism might be associated with schizophrenia.

Clinical characteristics and genetic analysis of two cases of pseudohypoparathyroidism type Ⅰa with early-onset skin nodules as the diagnostic clue / 中华皮肤科杂志

Clinical features of and genetic mutations in two cases of pseudohypoparathyroidism type Ⅰ a(PHP Ⅰ a) with early-onset skin nodules were analyzed.Both of the two patients were males,and their ages at onset were 2 and 3 months respectively.They both presented with early-onset skin nodules as the main clinical manifestation,and were clinically characterized by a round face,short neck and early obesity.Histopathological examination of skin lesions showed subcutaneous ectopic osteogenesis in both patients.The first patient had low blood calcium,high blood phosphorus,high parathyroid hormone (PTH),and gene sequencing showed a heterozygous mutation c.399delT causing a T base deletion at position 399 in exon 5 of the GNAS gene.The second patient had normal blood calcium and phosphorus levels as well as normal PTH levels at early stage,and gene sequencing showed a heterozygous mutation c.939delT causing a T base deletion at position 939 in exon 9 of the GNAS gene.The blood PTH level was found to increase in the second patient after 1-year follow-up.Both the patients were confirmedly diagnosed with PHP Ⅰa.After treatment with vitamin D3,no new skin nodules occurred,and the blood calcium and phosphorus levels returned to normal.

Clinical and gene methylation analysis of type 1b pseudohypoparathyroidism / 中华内分泌代谢杂志

Objective@#This study was carried out to analyze the clinical characteristics of pseudohypopara-thyroidism(PHP) type 1b, and to improve the understanding and diagnosis of the disease.@*Methods@#Five patients with molecular diagnosis of pseudohypoparathyroidism type 1b in our hospital during 2018 were enrolled, their clinical data, biochemical indicators, imaging, and gene detection results were analyzed.@*Results@#There were 4 females and 1 male, with low calcium, high phosphorus and high PTH serum concentrations. The onset age span was large and the onset symptoms were different. Family history may not be obvious. There was abnormal methylation of GNAS gene or deletion of exon STX16 in methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) detection while gene sequencing result was negative.@*Conclusion@#MS-MLPA detection was still needed in patients with suspected PHP but negative gene sequencing result. Different methylation abnormalities and copy number variations might be correlated with the onset symptoms and familial of type 1b PHP.

Clinical and gene methylation analysis of type 1b pseudohypoparathyroidism / 中华内分泌代谢杂志

Objective This study was carried out to analyze the clinical characteristics of pseudohypopara-thyroidism(PHP) type 1b, and to improve the understanding and diagnosis of the disease. Methods Five patients with molecular diagnosis of pseudohypoparathyroidism type 1b in our hospital during 2018 were enrolled, their clinical data, biochemical indicators, imaging, and gene detection results were analyzed. Results There were 4 females and 1 male, with low calcium, high phosphorus and high PTH seran con centrations. The onset age span was large and the onset symptoms were different. Family history may not be obvious. There wer was abnormal methylation of GNAS gene or deletion of exon STX16 in methylation-specific multiplex ligation-dependent probe amplification ( MS-MLPA ) detection while gene sequeming result was negative. Conclusion MS-MLPA detection was still needed in patients with suspected PHP but negative gene sequencing result. Different methylation abnormalities and copy number variations might be correlated with the onset symptoms and familial of type 1b PHP.

Study of major genetic factors involved in pituitary tumorigenesis and their impact on clinical and biological characteristics of sporadic somatotropinomas and non-functioning pituitary adenomas

Genetic and functional aberrations of guanine nucleotide-binding protein, alpha stimulating (GNAS), aryl hydrocarbon receptor interacting protein (AIP), and pituitary tumor transforming gene (PTTG) are among the most prominent events in pituitary tumorigenesis. A cohort of Brazilian patients with somatotropinomas (n=41) and non-functioning pituitary adenomas (NFPA, n=21) from a single tertiary-referral center were evaluated for GNAS and AIP mutations and gene expression of AIP and PTTG. Results were compared to the clinical and biological (Ki67 and p53 expression) characteristics of tumors and their response to therapy, if applicable. Genetic analysis revealed that 27% of somatotropinomas and 4.8% of NFPA harbored GNAS mutations (P=0.05). However, no differences were observed in clinical characteristics, tumor extension, response to somatostatin analog therapy, hormonal/surgical remission rates, Ki67 index, and p53 expression between mutated and non-mutated somatotropinomas patients. PTTG overexpression (RQ mean=10.6, min=4.39, max=11.9) and AIP underexpression (RQ mean=0.56, min=0.46-max=0.92) were found in virtually all cases without a statistically significant relationship with clinical and biological tumor features. No patients exhibited somatic or germline pathogenic AIP mutations. In conclusion, mutations in GNAS and abnormal PTTG and AIP expression had no impact on tumor features and treatment outcomes in this cohort. Our data support some previous studies and point to the need for further investigations, probably involving epigenetic and transcriptome analysis, to improve our understanding of pituitary tumor behavior.

Displasia fibrosa ósea / Fibrous dysplasia of bone

La displasia fibrosa ósea es un trastorno no hereditario del desarrollo esquelético caracterizado por una proliferación anormal de fibroblastos y diferenciación deficiente de osteoblastos que conduce a un reemplazo del tejido óseo esponjoso por tejido conectivo fibroso. Es producida por una mutación somática activadora del gen GNAS1 que induce una activación y proliferación de células mesenquimales indiferenciadas con formación de tejido fibroso y trabéculas óseas anómalas. Existen formas monostóticas, poliostóticas y craneofaciales con diversos grados de dolor, deformidades y fracturas óseas, aunque muchos casos son asintomáticos. En ocasiones se producen quistes óseos aneurismáticos, hemorragias, compromisos neurológicos y raramente osteosarcomas. Algunos casos se asocian a síndrome de McCune-Albright, síndrome de Mazabraud y a osteomalacia por hipofosfatemia por pérdida tubular renal inducida por el FGF23 producido por el tejido displásico. Los hallazgos en las radiografías convencionales son característicos, aunque variables y de carácter evolutivo. La gammagrafía ósea es la técnica de imagen con mayor sensibilidad para determinar la extensión de la enfermedad. El diagnóstico diferencial incluye múltiples lesiones óseas de características similares y en raras ocasiones se requiere biopsia ósea o estudio genético para confirmarlo. No existe un consenso unánime acerca del abordaje terapéutico de estos pacientes, razón por la cual es necesario un enfoque multidisciplinario. La conducta puede ser expectante o quirúrgica según el tipo de lesiones y es importante el manejo del dolor y de las endocrinopatías asociadas. La mayor experiencia publicada se refiere al uso de bifosfonatos y, más recientemente, denosumab. Los tratamientos actuales son insuficientes para modificar el curso de la enfermedad y es necesario el desarrollo de nuevas moléculas que actúen específicamente en el gen GNAS1 o sobre las células mesenquimales afectadas. (AU)

Fibrous dysplasia of bone is a noninherited developmental anomaly of bone characterized by abnormal proliferation of fibroblasts and differentiation of osteoblasts that cause a replacement of trabeculous bone by fibrous connective tissue. It is caused by a somatic mutation in the GNAS1 gene, which induces an undifferentiated mesenquimal cells activation and proliferation with formation of fibrous tissue and abnormal osseous trabeculae. There are monostotic, polyostotic and craniofacial variants with different grades of bone pain, deformities and fractures, although many cases remain asymptomatic. Aneurysmal bone cysts, bleeding, neurological compromise and infrequently osteosarcoma are possible complications. Some cases are associated to McCune-Albright syndrome, Mazabraud syndrome or hypophosphatemia and osteomalacia due to to renal tubular loss induced by FGF23 produced by dysplastic tissue. The findings on conventional radiography are characteristic although variable and evlolve with time. Bone scintigraphy is the most sensitive technique to evaluate the extent of disease. Differential diagnosis include several osseous lesions of similar appearance and, in some cases, bone biopsy or genetic testing may be necessary. Today, there is no consensus regarding the therapeutic approach for these patients and it is necessary a multidisciplinary medical team. Watchful waiting or surgical interventions can be indicated, depending on the type of bone lesions. Bone pain and associated endocrinopathies management are very important. Most published experience refers to the use of bisphosphonates and, more recently, denosumab. Current treatments are insufficient to modify the natural curse of the disease and therefore, new molecules with specific action on GNAS1 gene or affected mesenchymal cells are necessary. (AU)

A de novo mutation in GNAS cause severe pseudohypoparathyroidism typeⅠa / 临床儿科杂志

Objective To identify the GNAS gene mutation resulting in pseudohypoparathyroidism type Ⅰa (PHP-Ⅰa) in one patient. Methods The clinical data of a patient with pseudohypoparathyroidism type Ⅰa was retrospectively analyzed. All the 13 exons of GNAS were sequenced using Sanger method for the patient and the parents. The distribution of suspected causal mutation was screened in 478 healthy controls. To clarify the origin of the mutation, we performed targeted high-depth sequencing of GNAS exon harboring the mutation for the patient and the parents. Results The clinical data of the patient with the laboratory results of hypocalcaemia, hyperphosphataemia, elevated serum PTH, together with the features of AHO, conformed to the characterization of PHP-Ⅰa. The sequencing of GNAS exons identified a missense mutation (c.479G>C, p.R160P) located at exon 6 in the patient, which was absent in DNA of the parents. The mutation was not reported previously and was not found in the 478 healthy controls. We obtained about 8000-fold coverage from high-depth sequencing of DNA from peripheral blood of the patient and the parents. The disease-associated allele C identified in the patient was not observed in the parents. The number of reads with G allele (3984 reads) was roughly equal to that of C allele (4019 reads) from the targeted reanalysis of DNA of the patient. The results from high-depth sequencing indicated a de novo mutation in maternal germ cells. Conclusions We identified a new GNAS gene mutation (c.479G>C, p.R160P) caused PHP-Ia in a patient. Our results suggested the mutation was a maternal germline de novo mutation.

A Case of Pseudohypoparathyroidism Type Ib Caused by Aberrant Methylation in the GNAS Complex Locus

Pseudohypoparathyroidism (PHP) is a rare disorder caused by genetic and epigenetic aberrations in the GNAS complex locus resulting in impaired expression of stimulatory G protein (Gsα). PHP type Ib (PHP-Ib) is characterized by hypocalcemia and hyperphosphatemia due to renal resistance to the parathyroid hormone, and is distinguished from PHP-Ia by the absence of osteodystrophic features. An 11-yr-old boy presented with poor oral intake and cramping lower limb pain after physical activity. Laboratory studies revealed hypocalcemia, hyperphosphatemia, and increased parathyroid hormone levels. The GNAS complex locus was evaluated using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Gain of methylation in the NESP55 domain and loss of methylation in the antisense (AS) transcript, XL, and A/B domains in the maternal allele were observed. Consequently, we present a case of PHP-Ib diagnosed using MS-MLPA.

Analysis of clinical features and related genes variation in 41 girls with McCune-Albright syndrome / 中华内分泌代谢杂志

Objective To investigate the clinical characteristics and molecular pathological mechanism of McCune-Albright syndrome ( MAS) in order to provide a guidance for the precision medicine of MAS. Method The clinical data and genetic findings of 41 patients with MAS were analyzed retrospectively. Results (1) MAS girls had the phenotype of peripheral precocious puberty with premature sexual development and high estradiol, low LH and FSH, and the increased volume of uterus and ovary. ( 2 ) In 41 MAS cases, there were 17 cases with GNAS1 gene mutation, and the total positive rate was 41. 5%, of which the classic triad was 66. 7%, two signs 56. 3%, and 12. 5% in only one classic sign. GNAS1 gene mutation was found in 78. 6% of patients with polyostotic fibrous dysplasia of bone, while only 55. 0% in patients with cafe au lait skin spots. Children with precocious puberty and fibrous dysplasia of bone is an important basis for clinical diagnosis of MAS, but cafe au lait skin spots does not seem to be the specifical manifestation of MAS. Conclusion Clinically MAS was lack of typical clinical manifestations, and the most important clinical weight factor for the diagnosis of MAS was peripheral precocious puberty with fibrous dysplasia of bone. GNAS1 gene screening may be helpful to improve the clinical accurate diagnosis of MAS.

Progress of diagnosis and clinical management of pseudohypoparathyroidism / 中华实用儿科临床杂志

Pseudohypoparathyroidism(PHP) is a rare genetic disorder.The main character is parathyroid hormone resistance,and some with typical Albright's Hereditary Osteodystrothy malformation.The wide range of PHP symptom spectrum may lead to miss or misdiagnosis.This paper reviewed and summarized the pathogenesis,manifestation and the progress on the diagnosis and treatment of PHP Ⅰ,so as to improve the diagnostic level of this disease.

A Case of GNAS1 Mutation in Pseudohypoparathyroidism Type Ia

Pseudohypoparathyroidism (PHP) is a group of genetic disorders in which the kidneys fail to respond to parathyroid hormone. Genetic defects in the GNAS complex locus lead to reduced Gsalpha (alpha-subunit of the heterotrimeric stimulatory G protein) activity in PHP type Ia patients. These patients exhibit characteristics of Albright hereditary osteodystrophy (AHO) and hypocalcemia, increased parathyroid hormone, and resistance to other Gsalpha protein-coupled hormones. AHO has a wide range of manifestations such as short stature, obesity, round face, subcutaneous ossification, and bone shortening in the hands and feet. In this study, we present the case of a 47-yr-old woman who was diagnosed with PHP type Ia with AHO. She showed tetany, dizziness, irritability to light, decreased visual acuity, cognitive impairment, and motor dysfunction. Direct sequencing identified a heterozygous missense mutation in exon 6 (c.466G>A, p.Asp156Asn) in GNAS1. To our knowledge, this case is the first report in Korea of PHP type Ia caused by a heterozygous missense mutation in exon 6 (c.466G>A, p.Asp156Asn) in GNAS1.

Avaliação fenotípica e de defeitos moleculares no GNAS em pacientes com pseudo-hipoparatireoidismo (PHP) e pseudopseudo-hipoparatireoidismo (PPHP) / Evaluation of the phenotype and molecular defect in GNAS in patients with pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism

INTRODUÇÃO: A primeira doença humana atribuída à resistência hormonal foi o pseudo-hipoparatireoidismo (PHP), uma doença rara caracterizada por hipocalcemia, hiperfosfatemia e níveis elevados de hormônio paratireoidiano (PTH) na presença de função renal normal, quadro condizente com resistência ao PTH. A classificação original do PHP leva em consideração a osteodistrofia hereditária de Albright (AHO): presente no PHP1a e ausente no PHP1b. Na medida em que as bases moleculares do PHP têm sido compreendidas, uma classificação baseada no genótipo tem surgido. Segundo ela, pacientes com PHP1a apresentam mutações na região codificadora da Gsalfa do GNAS e o padrão de herança é autossômico dominante relacionado à transmissão materna. Por outro lado, o PHP1b é caracterizado por alterações nas regiões diferencialmente metiladas (DMRs) do GNAS por mecanismos não completamente esclarecidos, limitando a previsão do seu padrão de herança. Pacientes que apresentam a AHO na ausência de resistência hormonal têm o diagnóstico de pseudopseudo-hipoparatireoidismo (PPHP) e seu padrão de herança é autossômico dominante relacionado à transmissão paterna de mutações na região codificadora da Gsalfa do GNAS. OBJETIVOS: Classificar 25 pacientes com PHP com base em defeitos no GNAS e caracterizar seu fenótipo. Pesquisar mutações no GNAS nos quatro pacientes com PPHP e também caracterizar seu fenótipo. MÉTODOS: A avaliação fenotípica incluiu análise das resistências hormonais, pesquisa de repercussões crônicas da hipocalcemia/hiperfosfatemia (calcificações em sistema nervoso central: SNC e catarata) e identificação da AHO. A análise do GNAS foi feita por sequenciamento automático e MLPA (região codificadora da Gsalfa) e por MS-MLPA (região regulatória: DMRs). RESULTADOS: Resistência ao PTH foi identificada nos 25 pacientes com PHP e resistência ao TSH em 17/25. Calcificações em SNC e catarata estiveram presentes em 18 e 10 pacientes com PHP, respectivamente. A...

BACKGROUND: The first human disease attributed to hormone resistance was pseudohypoparathyroidism (PHP), a rare disease characterized by hypocalcemia, hyperphosphatemia and elevated parathyroid hormone (PTH) levels in the presence of normal renal function, consistent picture of PTH resistance. The original classification of PHP takes into account the Albright hereditary osteodystrophy (AHO): present in PHP1a and absent in PHP1b. As the molecular bases of PHP have been understood, a classification based on genotype has emerged. According to it, PHP1a patients present mutations in the Gsalpha coding region of the GNAS and the pattern of inheritance is autosomal dominant related to maternal transmission. On the other hand, PHP1b is characterized by alterations in differentially methylated regions (DMRs) of the GNAS by mechanisms not completely clear, limiting the prediction of the pattern of inheritance. Patients who present AHO in the absence of hormone resistance have the diagnosis of pseudopseudohypoparathyroidism (PPHP) and their pattern of inheritance is autosomal dominant related to paternal transmission of mutations in the Gsalfa coding region of the GNAS. OBJECTIVE: To classify 25 patients with PHP based on GNAS molecular defects and to characterize their phenotype. To search for GNAS mutations in four patients with PPHP and also to characterize their phenotype. METHODS: The phenotypic evaluation included analysis of hormone resistances, research of chronic repercussions of hypocalcemia/hyperphosphatemia (calcifications in central nervous system: CNS and cataract) and identification of AHO. The analysis of the GNAS was done by automated sequencing and MLPA (Gsalphaa coding region) and by MS-MLPA (regulatory region: DMRs). RESULTS: PTH resistance was identified in 25 patients with PHP and TSH resistance in 17/25. Calcifications in CNS and cataract were present in 18 and 10 patients with PHP, respectively. AHO was characterized by: rounded face (n=18),...

Identification of a novel mutation in a patient with pseudohypoparathyroidism type Ia / 소아과

Pseudohypoparathyroidism type Ia (PHP Ia) is a disorder characterized by multiform hormonal resistance including parathyroid hormone (PTH) resistance and Albright hereditary osteodystrophy (AHO). It is caused by heterozygous inactivating mutations within the Gs alpha-encoding GNAS exons. A 9-year-old boy presented with clinical and laboratory abnormalities including hypocalcemia, hyperphosphatemia, PTH resistance, multihormone resistance and AHO (round face, short stature, obesity, brachydactyly and osteoma cutis) which were typical of PHP Ia. He had a history of repeated convulsive episodes that started from the age of 2 months. A cranial computed tomography scan showed bilateral calcifications in the basal ganglia and his intelligence quotient testing indicated mild mental retardation. Family history revealed that the patient's maternal relatives, including his grandmother and 2 of his mother's siblings, had features suggestive of AHO. Sequencing of the GNAS gene of the patient identified a heterozygous nonsense mutation within exon 11 (c.637 C>T). The C>T transversion results in an amino acid substitution from Gln to stop codon at codon 213 (p.Gln213*). To our knowledge, this is a novel mutation in GNAS.

Analysis of promoter methylation of GNAS1 gene in pseudohypoparathyroidism type Ib / 中华内分泌代谢杂志

The methylation status of GNAS1 gene in pseudohypoparathyroidism type Ib patients was detected by methylation-specific PGR technique. There was an abnormal methylation of 1A region in all seven PHPIb patients. Loss of exon 1A methylation (imprinting defect) seems to be the cause of PHPIb.

A Case of McCune-Albright Syndrome with Associated Multiple Endocrinopathies

McCune-Albright syndrome (MAS) is a rare disorder that develops from an activating mutation in the Gs gene. It is characterized by an association with Polyostotic fibrous dysplasia, and precocious puberty, Caf-au-lait pigmentation, and other endocrinopathies that result from the hyperactivity of a variety of endocrine glands. Recently we encountered a patient with MAS with fibrous dysplasia, skin pigmentation, acromegaly, hyperprolactinemia and a thyroid nodule. A 23-year-old male presented for an evaluation of a change in his facial structures. Fibrous dysplasia was diagnosed by a bone biopsy and radiographic studies. The GH level increased paradoxically after an oral glucose load. The plasma prolactin, IGF-1 and alkaline phosphatase were high. Thyroid ultrasonography revealed multiple nodules. The brain MRI demonstrated a mass in the left pituitary gland. Genetic analysis identified a change from Arg (CGT) at codon 201 to Cys (TGT).

Mutational Analysis of Gsalpha Protein in Fibrous dysplasia of the Bone / 대한내분비학회지

BACKGROUND: Fibrous dysplasia of the bone(FD) is a benign fibrous bone lesion which usually involves the long bones of the extremities. FD may be asymptomatic, but often leads to bone deformity and pathological fracture. The disease is caused by a somatic mutation in the Gsalpha protein, which is responsible for intracellular signal transduction. METHODS: Mutations in the GNAS1 gene, which codes for Gsalpha protein, was investigated in 34 patients with monostotic and polyostotic FD and McCune-Albright syndrome. DNA was extracted from formalin-fixed, paraffin embedded bone tissues, and exons 8 and 9 of the GNAS1 gene amplified using a polymerase chain reaction(PCR). Subsequently, plasmid cloning and DNA sequencing analysis were performed. RESULTS: The PCR was successfully performed in 5 patients with monostotic FD. However, the sequencing analysis failed to identify any significant point mutations in exons 8 or 9 of GNAS1. Nevertheless, 3 point mutations were observed in the intron of the GNAS1 gene in 2 samples. CONCLUSION: In addition to the previously known somatic mutations of the GNAS1 gene, this study suggests that fibrous dysplasia of the bone might be associated with another point mutations of the GNAS1 gene