High Penetrance of Pheochromocytoma Associated with the Novel C634Y/Y791F Double Germline Mutation in the RET Protooncogene

Context: Previous studies have shown that double RET mutations may be associated with unusual multiple endocrine neoplasia type 2 (MEN 2) phenotypes. Objective: Our objective was to report the clinical features of patients harboring a previously unreported double mutation of the RET gene and to characterize this mutation in vitro. Patients: Sixteen patients from four unrelated families and harboring the C634Y/Y791F double RET germline mutation were included in the study. Results: Large pheochromocytomas measuring 6.0-14 cm and weighing upto 640 g were identified in the four index cases. Three of the four tumors were bilateral. High penetrance of pheochromocytoma was also seen in the C634Y/Y791F-mutation-positive relatives (seven of nine, 77.7%). Of these, two cases had bilateral tumors, one presented with multifocal tumors, two cases had large tumors (>5 cm), and one case, which was diagnosed with a large (5.5 x 4.5 x 4.0 cm) pheochromocytoma, reported early onset of symptoms of the disease (14 yr old). The overall penetrance of pheochromocytoma was 84.6% (11 of 13). Development of medullary thyroid carcinoma in our patients seemed similar to that observed in patients with codon 634 mutations. Haplotype analysis demonstrated that the mutation did not arise from a common ancestor. In vitro studies showed the double C634Y/Y791F RET receptor was significantly more phosphorylated than either activated wild-type receptor or single C634Y and Y791F RET mutants. Conclusions: Our data suggest that the natural history of the novel C634Y/Y791F double mutation carries a codon 634-like pattern of medullary thyroid carcinoma development, is associated with increased susceptibility to unusually large bilateral pheochromocytomas, and is likely more biologically active than each individual mutation. (J Clin Endocrinol Metab 95: 1318-1327, 2010)

The p.A2215D Thyroglobulin Gene Mutation Leads to Deficient Synthesis and Secretion of the Mutated Protein and Congenital Hypothyroidism with Wide Phenotype Variation

Context: Thyroglobulin (TG) is a large glycoprotein and functions as a matrix for thyroid hormone synthesis. TG gene mutations give rise to goitrous congenital hypothyroidism (CH) with considerable phenotype variation. Objectives: The aim of the study was to report the genetic screening of 15 patients with CH due to TG gene mutations and to perform functional analysis of the p. A2215D mutation. Design: Clinical evaluation and DNA sequencing of the TG gene were performed in all patients. TG expression was analyzed in the goitrous tissue of one patient. Human cells were transfected with expression vectors containing mutated and wild-type human TG cDNA. Results: All patients had an absent rise of serum TG after stimulation with recombinant human TSH. Sequence analysis revealed three previously described mutations (p. A2215D, p. R277X, and g. IVS30 + 1G > T), and two novel mutations (p. Q2142X and g. IVS46-1G > A). Two known (g. IVS30 + 1G/p. A2215D and p. A2215D/p. R277X) and one novel (p. R277X/g. IVS46-1G > A) compound heterozygous constellations were also identified. Functional analysis indicated deficiency in TG synthesis, reduction of TG secretion, and retention of the mutant TG within the cell, leading to an endoplasmic reticulum storage disease, whereas small amounts of mutant TG were still secreted within the cell system. Conclusion: All studied patients were either homozygous or heterozygous for TG gene mutations. Two novel mutations have been detected, and we show that TG mutation p. A2215D promotes the retention of TG within the endoplasmic reticulum and reduces TG synthesis and secretion, causing mild hypothyroidism. In the presence of sufficient iodine supply, some patients with TG mutations are able to compensate the impaired hormonogenesis and generate thyroid hormone. (J Clin Endocrinol Metab 94: 2938-2944, 2009)

A GPR54-activating mutation in a patient with central precocious puberty

Gonadotropin-dependent, or central, precocious puberty is caused by early maturation of the hypothalamic-pituitary-gonadal axis. In girls, this condition is most often idiopathic. Recently, a G protein-coupled receptor, GPR54, and its ligand, kisspeptin, were described as an excitatory neuroregulator system for the secretion of gonadotropin-releasing hormone (GnRH). In this study, we have identified an autosomal dominant GPR54 mutation - the substitution of proline for arginine at codon 386 (Arg386Pro) - in an adopted girl with idiopathic central precocious puberty (whose biologic family was not available for genetic studies). In vitro studies have shown that this mutation leads to prolonged activation of intracellular signaling pathways in response to kisspeptin. The Arg386Pro mutant appears to be associated with central precocious puberty.

Biliary and pancreatic dysgenesis in mice harboring a mutation in Pkhd1

Autosomal recessive polycystic kidney disease is a hereditary fibrocystic disease that involves the kidneys and the biliary tract. Mutations in the PKHD1 gene are responsible for typical forms of autosomal recessive polycystic kidney disease. We have generated a mouse model with targeted mutation of Pkbd1 by disrupting exon 4, resulting in a mutant transcript with deletion of 66 codons and expression at similar to 30% of wild-type levels. Pkhd1(del4/d3l4) mice develop intrahepatic bile duct proliferation with progressive cyst formation and associated periportal fibrosis. In addition, these mice exhibit extrahepatic manifestations, including pancreatic cysts, splenomegaly, and common bile duct dilation. The kidneys are unaffected both histologically and functionally. Fibrocystin is expressed in the apical membranes and cilia of bile ducts and distal nephron segments but is absent from the proximal tubule. This pattern is unchanged in orthologous models of autosomal dominant polycystic kidney disease due to mutation in Pkd1 or Pkd2. Mutant fibrocystin in Pkhd1(del4/d3l4) mice also retains this expression pattern. The hypomorphic Pkhd1(del4/d3l4) mouse model provides evidence that reduced functional levels of fibrocystin are sufficient for cystogenesis and fibrosis in the liver and pancreas, but not the kidney, and supports the hypothesis of species-dependent differences in susceptibility of tissues to Pkbdl mutations.

KISS1R Intracellular Trafficking and Degradation: Effect of the Arg386Pro Disease-Associated Mutation

The goal of this study was to investigate how the Arg386Pro mutation prolongs KiSS-1 receptor (KISS1R) responsiveness to kisspeptin, contributing to human central precocious puberty. Confocal imaging showed colocalization of wild-type (WT) KISS1R with a membrane marker, which persisted for up to 5 h of stimulation. Conversely, no colocalization with a lysosome marker was detected. Also, overnight treatment with a lysosome inhibitor did not affect WT KISS1R protein, whereas overnight treatment with a proteasome inhibitor increased protein levels by 24-fold. WT and Arg386Pro KISS1R showed time-dependent internalization upon stimulation. However, both receptors were recycled back to the membrane. The Arg386Pro mutation did not affect the relative distribution of KISS1R in membrane and internalized fractions when compared to WT KISS1R for up to 120 min of stimulation, demonstrating that this mutation does not affect KISS1R trafficking rate. Nonetheless, total Arg386Pro KISS1R was substantially increased compared with WT after 120 min of kisspeptin stimulation. This net increase was eliminated by blockade of detection of recycled receptors, demonstrating that recycled receptors account for the increased responsiveness of this mutant to kisspeptin. We therefore conclude the following: 1) WT KISS1R is degraded by proteasomes rather than lysosomes; 2) WT and Arg386Pro KISS1R are internalized upon stimulation, but most of the internalized receptors are recycled back to the membrane rather than degraded; 3) the Arg386Pro mutation does not affect the rate of KISS1R trafficking-instead, it prolongs responsiveness to kisspeptin by decreasing KISS1R degradation, resulting in the net increase on mutant receptor recycled back to the plasma membrane.(Endocrinology 152: 1616-1626,2011)

Anti-Group A Streptococcal Vaccine Epitope STRUCTURE, STABILITY, AND ITS ABILITY TO INTERACT WITH HLA CLASS II MOLECULES

Streptococcus pyogenes infections remain a health problem in several countries due to poststreptococcal sequelae. We developed a vaccine epitope (StreptInCor) composed of 55 amino acids residues of the C-terminal portion of the M protein that encompasses both T and B cell protective epitopes. The nuclear magnetic resonance (NMR) structure of the StreptInCor peptide showed that the structure was composed of two microdomains linked by an 18-residue alpha-helix. A chemical stability study of the StreptInCor folding/unfolding process using far-UV circular dichroism showed that the structure was chemically stable with respect to pH and the concentration of urea. The T cell epitope is located in the first microdomain and encompasses 11 out of the 18 alpha-helix residues, whereas the B cell epitope is in the second microdomain and showed no alpha-helical structure. The prediction of StreptInCor epitope binding to different HLA class II molecules was evaluated based on an analysis of the 55 residues and the theoretical possibilities for the processed peptides to fit into the P1, P4, P6, and P9 pockets in the groove of several HLA class II molecules. We observed 7 potential sites along the amino acid sequence of StreptInCor that were capable of recognizing HLA class II molecules (DRB1*, DRB3*, DRB4*, and DRB5*). StreptInCoroverlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules and could be considered as a universal vaccine epitope.

A novel TBX5 missense mutation (V263M) in a family with atrial septal defects and postaxial hexodactyly

Background: Congenital heart diseases are the most frequent birth defects and are commonly associated with skeletal malformations. Mutations in the TBX5 gene, a T-box transcription factor located on chromosome 12q24.1, have been demonstrated to be the underlying molecular alteration in individuals with different congenital cardiac disorders, notably the Holt-Oram syndrome. Methods: Six members from a two-generation family from a consanguineous couple, which had atrial septal defects associated with postaxial hexodactyly in all extremities were clinically assessed and submitted to TBX5 mutational analysis performed by direct sequencing. Results: We detected a new TBX5 missense mutation (V263M) in all four individuals studied with cardiac abnormalities. The genotype phenotype correlations in light of unusual features are extensively discussed, as well as the possible significance of these atypical findings. Conclusions: These new data extend our clinical and molecular knowledge of TBX5 gene mutations and also raise interesting questions about the phenotype heterogeneity regarding these gene alterations. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Generation and phenotypic characterization of new human ovarian cancer cell lines with the identification of antigens potentially recognizable by HLA-restricted cytotoxic T cells

This study describes a simple method for long-term establishment of human ovarian tumor lines and prediction of T-cell epitopes that could be potentially useful in the generation of tumor-specific cytotoxic T lymphocytes (CTLs), Nine ovarian tumor lines (INT.Ov) were generated from solid primary or metastatic tumors as well as from ascitic fluid, Notably all lines expressed HLA class I, intercellular adhesion molecule-1 (ICAM-1), polymorphic epithelial mucin (PEM) and cytokeratin (CK), but not HLA class II, B7.1 (CD80) or BAGE, While of the 9 lines tested 4 (INT.Ov1, 2, 5 and 6) expressed the folate receptor (FR-alpha) and 6 (INT.Ov1, 2, 5, 6, 7 and 9) expressed the epidermal growth factor receptor (EGFR); MAGE-1 and p185(HER-2/neu) were only found in 2 lines (INT.Ov1 and 2) and GAGE-1 expression in 1 line (INT.Ov2). The identification of class I MHC ligands and T-cell epitopes within protein antigens was achieved by applying several theoretical methods including: 1) similarity or homology searches to MHCPEP; 2) BIMAS and 3) artificial neural network-based predictions of proteins MACE, GAGE, EGFR, p185(HER-2/neu) and FR-alpha expressed in INT.Ov lines, Because of the high frequency of expression of some of these proteins in ovarian cancer and the ability to determine HLA binding peptides efficiently, it is expected that after appropriate screening, a large cohort of ovarian cancer patients may become candidates to receive peptide based vaccines. (C) 1997 Wiley-Liss, Inc.

A new FOXL2 gene mutation in a woman with premature ovarian failure and sporadic blepharophimosis-ptosis-epicanthus inversus syndrome

Objective: To describe a new FOXL2 gene mutation in a woman with sporadic blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) and hypergonadotropic hypogonadism. Design: Case report. Setting: University medical center. Patient(s): A 28-year-old woman. Intervention(s): Clinical evaluation, hormone assays, gene mutation research. Main Outcome Measure(s): FOXL2 gene mutation. Result(s): The patient with hypergonadotropic hypogonadism was diagnosed with BPES due to a new FOXL2 gene mutation. Conclusion(s): Blepharophimosis-ptosis-epicanthus inversus syndrome is a rare disorder associated with premature ovarian failure (POF). The syndrome is an autosomal dominant trait that causes eyelid malformations and POF in affected women. Mutations in FOXL2 gene, located in chromosome 3, are related to the development of BPES with POF (BPES type I) or without POF (BPES type II). This report demonstrates a previously undescribed de novo mutation in the FOXL2 gene-a thymidine deletion, c. 627delT (g. 864delT)-in a woman with a sporadic case of BPES and POF. This mutation leads to truncated protein production that is related to a BPES type I phenotype. This report shows the importance of family history and genetic analysis in the evaluation of patients with POF and corroborates the relationship between mutations on the FOXL2 gene and ovarian insufficiency. (Fertil Steril (R) 2010; 93: 1006.e3-e6. (C) 2010 by American Society for Reproductive Medicine.)

TNF receptor-associated periodic syndrome (TRAPS): Description of a novel TNFRSF1A mutation and response to etanercept

TRAPS is the most common of the autosomal dominant periodic fever syndromes. It is caused by mutations in the TNFRSF1A gene, which encodes for the type 1 TNF-receptor (TNFR1). We describe here a Brazilian patient with TRAPS associated to a novel TNFRSF1A de novo mutation and the response to anti-TNF therapy. The patient is a 9-year-old girl with recurrent fevers since the age of 3 years, usually lasting 3 to 7 days, and recurring every other week. These episodes are associated with mild abdominal pain, nausea, vomiting and generalized myalgia. Recurrent conjunctivitis and erysipela-like skin lesions in the lower limbs also occur. Laboratory studies show persistent normocytic normochromic anemia, thrombocytosis, elevated erythrocyte sedimentation rate and C-reactive protein. IgD levels are normal. Mutational screening of TNFRSF1A revealed the association of a novel C30F mutation with the common R92Q low-penetrance mutation. The R92Q mutation is seen in 5% of the general population and is associated with an atypical inflammatory phenotype. The patient had a very good response to etanercept, with cessation of fever and normalization of inflammatory markers. Our report expands the spectrum of TNFRSF1A mutations associated with TRAPS, adding further evidence for possible additive effects of a low-penetration R92Q and cysteine residue mutations, and confirms etanercept as an efficacious treatment alternative.

Phenotype-genotype analysis of cryopyrin-associated periodic syndromes (CAPS): Description of a rare non-exon 3 and a novel CIAS1 missense mutation

We describe in this paper the phenotype-genotype analysis of a Brazilian cohort of patients with cryopyrin-associated periodic syndromes (CAPS). Patient 1 presented with an urticarial rash and recurrent fever exacerbated by cold weather, arthritis, and anterior uveitis, thus, receiving a clinical diagnosis of familial cold autoinflammatory syndrome. CIAS1 sequencing identified the T436I mutation, previously associated to a clinical phenotype of chronic infantile neurological cutaneous and articular/neonatal onset multisystem inflammatory disease. Patient 2 developed a papular exanthema with daily fever shortly after birth, frontal bossing, patellae enlargement, and cognitive and motor impairments. Sequencing identified the exceedingly rare G755R CIAS1 mutation in exon 4. Patient 3 developed skin rash and articular symptoms 6 h after birth, followed by aseptic meningitis. He was found to have the novel C148Y missense mutation in CIAS1. This report expands the spectrum of CIAS1 mutations associated to clinical disease, suggests that the same mutation can be associated with different clinical syndromes, and supports the evidence that CAPS patients should always be screened for mutations outside exon 3.

Distinct resistance mutation and polymorphism acquisition in HIV-1 protease of subtypes B and F1 from children and adult patients under virological failure

The goal of this work was to compare the differences between human immunodeficiency Virus type 1 (HIV-1) of B and F1 Subtypes in the acquisition of major and rninot- protease inhibitor (P1)-associated resistance mutations and of other polymorphisms at the protease (PR) gene, through a cross sectional Study. PR sequences from subtypes B and F1 isolates matched according to P1 exposure time from Brazilian patients were included in this study. Sequences were separated in four groups: 24 and 90 from children and 141 and 99 from adults infected with isolates of subtypes F1 and B, respectively. For comparison, 211 subype B and 79 subtype F1 PR sequences from drug-naive individuals Were included. Demographic and clinical data were similar among B- and F1-infected patients. In untreated patients, Mutations L1OV, K20R, and M361 were more frequent in subtype F1, while L63P, A7IT, and V771 were more prevalent in Subtype B. In treated patients, K20M, D30N, G73S, 184V, and L90M, were More prevalent in subtype B, and K20T and N88S Were more prevalent in Subtype F1. A higher proportion of subtype F1 than Of subtype B Strains Containing other polymorphisms was observed. V82L mutation was Present With increased frequency in isolates from children compared to isolates from adults infected with both subtypes. We could observe a faster resistance emergence in children than in adults, during treatment with protease inhibitors. This data provided evidence that, although rates of overall drug resistance do not differ between subtypes B and F1, the former accumulates resistance at higher proportion in specific amino acid positions of protease when compared to the latter. (c) 2008 Elsevier B.V. All rights reserved.

Multiple endocrine neoplasia type 1 in Brazil: MEN1 founding mutation, clinical features, and bone mineral density profile

Objective: Only few large families with multiple endocrine neoplasia type 1 (MEN1) have been documented. Here, we aimed to investigate the clinical features of a seven-generation Brazilian pedigree. which included 715 at-risk family members. Design: Genealogical and geographic analysis was used to identify the MEN1 pedigree. Clinical and genetic approach was applied to characterize the phenotypic and genotypic features of the family members. Results: Our genetic data indicated that a founding mutation in the MEN1 gene has occurred in this extended Brazilian family. Fifty family members were diagnosed with MEN1. Very high frequencies of functioning and non-functioning MEN1-related tumors were documented and the prevalence of prolactinoma (29.6%) was similar to that previously described in prolactinoma-variant Burin (32%). In addition, bone mineral density analysis revealed severe osteoporosis (T,-2.87 +/- 0.32) of compact bone (distal radius) in hyperparathyroidism (HPT)/MEN1 patients. while marked bone mineral loss in the lumbar spine (T,-1.95 +/- 0.39). with most cancellous bone, and femoral neck (mixed composition: T,-1.48 +/- 0.27) were also present. Conclusions: In this study, we described clinically and genetically the fifth largest MEN1 family in the literature. Our data confirm previous findings suggesting that prevalence of MEN1-related tumors in large families may differ from reports combining cumulative data of small families. Furthermore. we were able to evaluate the bone status in HPT/MEN1 cases, a subject that has been incompletely approached in the literature. We discussed the bone loss pattern found in our MEN1 patients comparing with that of patients with sporadic primary HPT.

A novel WT1 heterozygous nonsense mutation (p.K248X) causing a mild and slightly progressive nephropathy in a 46,XY patient with Denys-Drash syndrome

WT1 mutations have been described in a variety of syndromes, including Denys-Drash syndrome (DDS), which is characterized by predisposition to Wilms` tumor, genital abnormalities and development of early nephropathy. The most frequent WT1 defects in DDS are missense mutations located in exons 8-9. Our aim is to report a novel WT1 mutation in a 46,XY patient with a DDS variant, who presented a mild nephropathy with a late onset diagnosed during adolescence. He had ambiguous genitalia at birth. At 4 months of age he underwent nephrectomy (Wilms` tumor) followed by chemotherapy. Ambiguous genitalia were corrected and bilateral gonadectomy was performed. Sequencing of WT1 identified a novel heterozygous mutation (c.742A > T) in exon 4 that generates a premature stop codon (p.K248X). Interestingly, this patient has an unusual DDS nephropathy progression, which reinforces that patients carrying WT1 mutations should have the renal function carefully monitored due to the possibility of late-onset nephropathy.