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PubMed1995

Pancreatic insufficiency and pulmonary disease in German and Slavic cystic fibrosis patients with the R347P mutation.

Cystic fibrosis (CF) is caused by mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) that codes for a cAMP-regulated chloride channel. The R347P is a missense mutation located within the first membrane spanning domain (MSD1) of the CFTR protein. This mutation occurs with an overall worldwide frequency of about 0.2%. The patients, originally described with this mutation were compound heterozygotes with the delta F508 mutation and had a very mild course of CF, suggesting that R347P, similar to other missense mutations affecting the MSD1 domain, causes a mild phenotype. We report here a group of 19 CF patients with the R347P mutation of German, Bulgarian, Czech, and Slovak origin, including two homozygotes. Most patients presented with early disease onset, pancreas insufficiency (PI), and early pulmonary involvement, suggesting that this mutation can lead to a severe course of CF. Most R347P alleles in the group studied share a common polymorphic haplotype. In addition, these analyses gave evidence for recurrence of the mutation in two CF patients of German and Czech origin.

Cystic Fibrosis↗
PubMed2001

Factor V Leiden and prothrombin G20210A in relation to arterial and/or vein rethrombosis: two cases.

The factor V Leiden (FV Leiden) and prothrombin G20210A mutations, are the most common established genetic risk factors for deep vein thrombosis (DVT). However, the relationship between these mutations and arterial thrombotic syndromes (coronary heart disease, myocardial infarction, stroke) has not been established. Some studies have suggested a relationship between them, but other authors have considered it unlikely that these anomalies are a major risk factor for arterial thrombosis. From the clinical point of view, a question arises concerning the risk of repeated thrombosis in patients carrying one of these two mutations. The question is whether the recurrence is attributable to the mutations or to the presence of additional circumstantial risk factors. As the risk of repeated thrombosis varies considerably from one patient to another, decisions about long-term treatment require weighing the persistence of risk factors for vascular disease (venous and arterial), especially in selected cases such as young patients or patients with thrombosis of unusual localization.

3' Untranslated Regions↗
PubMed2001

The fibroblast growth factor receptor 3 (FGFR3) mutation is a strong indicator of superficial bladder cancer with low recurrence rate.

We analyzed the possible prognostic value of the recently discovered fibroblast growth factor receptor 3 (FGFR3) mutations in bladder cancer. A FGFR3 mutation was found in 34 of 53 pTaG1-2 bladder cancers, whereas none of the 19 higher-staged tumors had a mutation (P < 0.0001). In 57 patients with superficial disease followed prospectively by cystoscopy for 12 months, 14 of 23 patients in the wild-type FGFR3 group developed recurrent bladder cancer compared with only 7 of 34 patients in the mutant group (P = 0.004). The recurrence rate per year was 0.24 for the FGFR3 mutant tumors and 1.12 for tumors with a wild-type FGFR3 gene. In addition, FGFR3 mutation status was the strongest predictor of recurrence when compared with stage and grade (P = 0.008). This is the first mutation in bladder cancer that selectively identifies patients with favorable disease characteristics. Our results suggest that the frequency of cystoscopic examinations can be reduced considerably in patients with FGFR3-positive tumors.

Adult↗
PubMed2001

Analysis of BCL-6 mutations in classic Hodgkin disease of the B- and T-cell type.

BCL-6 is essential for germinal center formation and thus for affinity maturation of immunoglobulin (Ig) genes by somatic mutations. The 5'-noncoding region of the BCL-6 gene is even a target for the mutation machinery. Translocations of the BCL-6 gene to heterologous promoters and mutations of its 5'-noncoding regulatory region were reported to be potential mechanisms for deregulating BCL-6 expression and for playing a role in the genesis of non-Hodgkin lymphoma. In line with this hypothesis is the observation that B-cell lymphoma with somatic mutations, such as diffuse large B-cell lymphoma and follicular lymphoma, also carry BCL-6 mutations, some of which are recurrently detectable. Classic Hodgkin disease (cHD) is also derived from B cells with high loads of somatic mutations and thus a further candidate for BCL-6 mutations. To determine the presence and potential role of BCL-6 mutations in cHD, the 5'-noncoding BCL-6 proportion of single Hodgkin and Reed-Sternberg (HRS) cells from 6 cases of cHD and 6 cases of HD-derived cell lines was analyzed. All B-cell-derived HD cases and cell lines harbored BCL-6 mutations. In contrast, both T-cell-derived HD cases and cell lines were devoid of BCL-6 mutations. With only one exception, there were no lymphoma-specific recurrent BCL-6 mutations detected, and BCL-6 protein was absent from the HRS cells of most cases. In conclusion, (1) somatic BCL-6 mutations are restricted to cHD cases of B-cell origin, and (2) the BCL-6 mutations represent mostly irrelevant somatic base substitutions without consequences for BCL-6 protein expression and the pathogenesis of cHD.

5' Untranslated Regions↗
PubMed2006

Specific TP53 mutation pattern in radiation-induced sarcomas.

The mutagenic properties of ionizing radiation are well known, but the presence of specific mutations in human radiation-induced tumours is not established. We have studied a series of 36 secondary sarcomas arising in the irradiation field of a primary tumour following radiotherapy. The allelic status and the presence of mutations of the TP53 gene were investigated. The mutation pattern was compared with data from sporadic sarcomas recorded in the IARC TP53 somatic mutations database. A high proportion (58%) of the radiation-induced sarcomas exhibited a somatic inactivating mutation for one allele of TP53, systematically associated with a loss of the other allele. The high frequency (52%) of short deletions observed in the mutation pattern of radiation-induced sarcomas may be related to the induction of DNA breaks by ionizing radiation. The lack of hyper-reactivity of CpG dinucleotides and the presence of recurrent sites of mutation at codons 135 and 237 seem also to be specific for radiation tumorigenesis.

Adult↗
PubMed2025

Genomic subtypes of non-muscle-invasive bladder cancer: guiding immunotherapy decision-making for patients exposed to aristolochic acid.

BACKGROUND: The limited genomic data on non-muscle-invasive bladder cancer (NMIBC) hampers our understanding of its carcinogenesis and development. Specifically, Aristolochic acid (AA), a potent human carcinogenic compound from aristolochia plants and commonly found in Chinese herbal medicine, has been extensively documented as being closely associated with the onset and progression of bladder cancer. However, the field of AA-induced NMIBC remains largely unexplored in terms of its genomic and molecular characteristics, as well as clinical therapeutic strategies. METHODS: To bridge this knowledge gap, we conducted a comprehensive study using a cohort of 81 NMIBC samples. We performed whole-exome sequencing (WES) and RNA sequencing (RNA-seq) to obtain detailed genomic and transcriptomic data. We subjected these datasets to genomic analysis and subtype analysis to gain valuable insights into NMIBC. RESULTS: By temporally dissecting mutations in NMIBC specimens, we identified a comprehensive mutational landscape of NMIBC and the associations of these mutations with recurrence-free survival. Additionally, we discerned four genomic subtypes of NMIBC: AA-like, FGFR3/HRAS, FGFR3 & chr9Del, and genome instability (GI). The AA-like subtype presented a high frequency of gene mutations along with a pronounced AA mutagenesis signature of SBS22 (Fisher test: P-value 3.5e-4, OR 25.25) even after temporal dissection. The FGFR3/HRAS subtype exhibited FGFR3 or HRAS mutations with few copy number alterations (CNAs). The FGFR3 & chr9Del subtype was characterized by the co-occurrence of chr9p and chr9q deletions as well as FGFR3 mutations, while the GI subtype showed a high frequency of CNAs. Notably, the AA-like and GI subtypes demonstrated better outcomes after immunotherapy, whereas the FGFR3/HRAS subtype showed poorer outcomes. CONCLUSIONS: Our findings provide novel perspectives on the genomics of NMIBC, unveiling four prominent genomic subtypes, each showing different outcomes following immunotherapy. TRIAL REGISTRATION: No. 2019PHB268-01 (retrospectively registered on February 14, 2020).

Humans↗
PubMed2005

LMNA mutations in progeroid syndromes.

Segmental progeroid syndromes are disorders in which affected individuals. present various features that suggest accelerated ageing. The two best-known examples are Hutchinson-Gilford progeria syndrome (HGPS, 'Progeria of childhood') and Werner syndrome (WS, 'Progeria of the adult'). A novel, recurrent de novo mutation in the LMNA gene, responsible for the majority of HGPS cases, results in an in-frame deletion of 50 amino acids, including endoproteolytic sites required for processing of prelamin A to mature lamin A protein. Another mutation results in a 35 amino acid in-frame deletion with a milder HGPS phenotype. WRN, the gene responsible for the majority of WS cases, encodes a multifunctional nuclear protein with exonuclease and helicase activities and may participate in optimizing DNA repair/recombination. A subset of WS patients do not show mutations at the WRN locus (atypical WS), but show heterozygous amino acid substitutions in the heptad repeat region of lamin A. Structural analysis suggests that mutations in atypical WS may interfere with protein-protein interactions. When compared to WRN-mutant WS, LMNA-mutant atypical WS patients appear to show earlier onset and possibly more severe ageing-related symptoms.

Animals↗
PubMed1999

Hypercoagulable state mutation analysis in white patients with early first-trimester recurrent pregnancy loss.

OBJECTIVE: Antiphospholipid antibodies (APA) and other coagulation abnormalities have been associated with an increased risk of venous, arterial, and placental thrombosis and recurrent pregnancy loss (RPL). Factor V Leiden (a point mutation [1691G-->A] in the factor V gene), the prothrombin 20210G-->A mutation, and homozygosity for a common polymorphism in the methylene tetrahydrofolate reductase (MTHFR) gene (677C-->T) have been associated with arterial and venous thrombosis and arterial occlusive disease. We explored an association between these markers of thrombophilic states and RPL. DESIGN: Prospective case-control evaluation. SETTING: University-associated private practice. PATIENT(S): Fifty nonpregnant women with three or more pregnancy losses and 50 healthy, nonpregnant controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Anticardiolipin and antiphosphatidylserine antibodies were detected in serum by ELISA. Polymerase chain reaction was performed to identify the factor V Leiden (1691G-->A) mutation, the thermobile MTHFR (677C-->T) mutation, and the prothrombin 20210G-->A mutation. RESULT(S): The following were identified by restriction fragment-linked polymorphism analyses: 1 (2%) factor V Leiden heterozygosity; 1 (2%) prothrombin 20210G-->A heterozygosity; and 4 (8%) thermolabile MTHFR homozygosity. None of these mutation frequencies in women with RPL were statistically significantly different from controls. CONCLUSION(S): These data suggest that factor V Leiden, thermolabile MTHFR (677C-->T), and prothrombin 20210G-->A are not found at an increased frequency in women with a history of early RPL.

Abortion, Habitual↗
PubMed1996

A common insertion mutation in COL7A1 in two Italian families with recessive dystrophic epidermolysis bullosa.

Recessive dystrophic epidermis bullosa is ultrastructurally characterized by the absence of anchoring fibrils, and genetic analyses have revealed that recessive dystrophic epidermolysis bullosa results from mutations in the type VII collagen gene (COL7A1). The mutations disclosed thus far are largely family specific, with no evidence for mutational hotspot(s). In this study, we report a recurrent premature termination codon mutation detected in two apparently unrelated Italian families in different regions of the country. This mutation, 497insA in exon 4 of COL7A1, was found in combination with two different premature termination codon mutations in these families. Haplotype analysis suggested a shared genetic background in the allele containing the mutation 497insA, suggesting that this genetic lesion may represent an ancestral mutation within the Italian gene pool.

Adult↗
PubMed2002

Clinical and molecular basis of classical lissencephaly: Mutations in the LIS1 gene (PAFAH1B1).

Classical lissencephaly (LIS) and subcortical band heterotopia (SBH) are related cortical malformations secondary to abnormal migration of neurons during early brain development. Approximately 60% of patients with classical LIS, and one patient with atypical SBH have been found to have deletions or mutations of the LIS1 gene, located on 17p13.3. This gene encodes the LIS1 or PAFAH1B1 protein with a coiled-coil domain at the N-terminus and seven WD40 repeats at the C-terminus. It is highly conserved between species and has been shown to interact with multiple proteins involved with cytoskeletal dynamics, playing a role in both cellular division and motility, as well as the regulation of brain levels of platelet activating factor. Here we report 65 large deletions of the LIS1 gene detected by FISH and 41 intragenic mutations, including four not previously reported, the majority of which have been found as a consequence of the investigation of 220 children with LIS or SBH by our group. All intragenic mutations are de novo, and there have been no familial recurrences. Eight-eight percent (36/41) of the mutations result in a truncated or internally deleted protein-with missense mutations found in only 12% (5/41) thus far. Mutations occurred throughout the gene except for exon 7, with clustering of three of the five missense mutations in exon 6. Only five intragenic mutations were recurrent. In general, the most severe LIS phenotype was seen in patients with large deletions of 17p13.3, with milder phenotypes seen with intragenic mutations. Of these, the mildest phenotypes were seen in patients with missense mutations.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1996

Detection of p53 auto-antibodies in the sera of breast cancer patients with a new recurrence using an ELISA assay. Does a correlation with the recurrence free interval exist?

INTRODUCTION: Mutations of the tumor suppressor gene p53 are common in multiple cancer forms, including breast cancer. Data are available that suggest, that the loss of the wild type form of p53 and the appearance of the mutant forms of p53 are correlated with a poorer overall survival rate in patients with breast cancer. The accumulation of the mutant forms of p53 in the cytoplasmatic rooms of the tumor cells leads to the production of human auto-antibodies against these mutant p53 proteins. Therefore, the aim of this study was to analyse and quantify the levels of serum auto-antibodies against p53 protein in patients with an intact immunological system having an active and new recurrence of breast cancer and to compare the obtained results with the recurrence free interval and with established prognostic parameters at the time of first diagnosis, to see if patients with a positive p53 auto-antibody status had a poorer prognosis than those who were p53 auto-antibody positive. MATERIALS AND METHODS: The ser of 61 patients with breast cancer, who experienced a new, clinical and biophysically identified local or distant recurrence and that showed an intact immunological system were analysed with an ELISA assay of Dianova to determine the concentration of auto-antibodies against mutant p53. RESULTS: 14.5% of the patients showed a positive p53 auto-antibody serum status. The recurrence free interval between the p53 auto-antibody positive and negative patients was almost the same: 4.12 years for the p53 auto-antibody positive patients versus 3.72 years for the p53 auto-antibody negative patients (independent t-test value = 0.224 and p value = 0.824; statistically not a significant difference). When comparing the p53 auto-antibody status with established prognostic parameters we could only find a statistically significant correlation with tumor size. No correlations were obtained when comparing the p53 auto-antibody status with the N- and M status, the ER- and PR status, the menopausal status and the cathepsin-D status. DISCUSSION: We were able to demonstrate that the expression of serum auto-antibodies against mutant p53 can not be used as a prognostic parameter in patients with breast cancer as the recurrence free interval between the p53 auto-antibody positive and negative patients did not differ. The determination of the auto-antibodies against p53, though easy to perform, is therefore not a test that helps clinicians in their treatment options, but it remains a useful test for the description of the biological mechanisms of breast cancer.

Autoantibodies↗
PubMed2001

EGR2 mutation R359W causes a spectrum of Dejerine-Sottas neuropathy.

Heterozygous mutations in the early growth response gene 2 (EGR2), which encodes a zinc-finger transcription factor that regulates the late stages of myelination, cause myelinopathies including congenital hypomyelinating neuropathy, Dejerine-Sottas neuropathy (DSN), and Charcot-Marie-Tooth disease type 1. We screened 170 unrelated neuropathy patients without mutations involving the peripheral myelin protein 22 gene (PMP22), the myelin protein zero gene (MPZ), or the gap junction protein beta1 gene (GJB1) and identified two DSN patients with the heterozygous mutation R359W in the alpha-helix domain of the first zinc-finger of EGR2. We now report that this mutation is a recurrent cause of DSN, and that expressivity ranges from that typical for DSN to a more rapidly progressive neuropathy that can cause death by age 6 years. Furthermore, in contrast to patients with typical DSN, patients with the EGR2 R359W mutation have more respiratory compromise and cranial nerve involvement.

Amino Acid Substitution↗
PubMed1995

Oncogene protein co-expression. Value of Ha-ras, c-myc, c-fos, and p53 as prognostic discriminants for breast carcinoma.

OBJECTIVE: A refinement of prognostic variables using traditional pathologic markers integrated with oncogene proteins, enzymes, and hormonal factors may enhance the ability to predict for recurrence or survival in patients with mammary carcinoma. Although various oncogenes and oncogene products have been identified in human breast carcinoma, their relationship to disease outcome remains controversial. METHODS: Using the monoclonal antibodies cS93.1, 9E1.0, F235-1.7.1, and PAb 1801 against each oncogene protein studied, the avidin-biotin complex immunoperoxidase method provided immunohistochemical staining of bound oncogene protein for c-fos, c-myc, Ha-ras, and p53, respectively. Analyses were made on archival pathology tissues of 85 breast cancer patients (stages I, IIA, and IIB). Forty patients (47%) had recurrence of disease; 45 remained free of local-regional or distant disease at mean follow-up of 48 months (range 6-180 months). Molecular biological data were merged with clinicopathologic demographics 1) to determine the frequency of single or co-expression of oncogenes in this patient population; 2) to evaluate the value of these molecular protein markers to predict probability of recurrence; and 3) to determine worth of the studied oncogenes to correlate with traditional clinical pathologic parameters and overall survival. RESULTS: In this study, oncogene expression had statistical correlation for recurrence with increasing co-expression: one oncogene 17.2%, two oncogenes 56.3%, three or four oncogenes, 100% (p = 0.001). Increasing oncogene or co-oncogene expression correlated with statistically significant reduction in disease-free and overall survival; with no expression of oncogenes, disease-free survival was 30 (SE +/- 5.7) months and overall survival was 56.4 (SE +/- 4.57) months. With expression of three oncogenes, disease-free survival was 12 (SE +/- 1.23) months (p = 0.0018) and overall survival was 23.4 (SE +/- 3.38) months (p = 0.0025). In univariate Wilcoxon analysis, oncogene expression was the most significant variable to determine survival (p = 0.035); in multivariate analysis, age and oncogene co-expression each emerged as the most significant variables for overall survival. For the proportional hazards regression model, oncogene co-expression was significant (p = 0.0104, risk-ratio 1.914) and correlated with age and tumor size as significant variables. Ha-ras and c-fos both emerged as important individual oncogene proteins to affect survival (p = 0.0925, risk-ratio 3.517 and p = 0.025, risk-ratio 4.214, respectively). The proto-oncogene c-myc and the antitumor suppressor gene p53 did not have significant effects as individual oncogenes to influence survival. CONCLUSIONS: Approximately one fifth of the breast cancer patients in this analysis (disease-free and recurrent) expressed only a single oncogene marker (c-fos, c-myc, Ha-ras, or p53); one quarter of patients with recurrent disease expressed only one oncogene protein. Single oncogene expression did not possess independent prognostic significance for prediction of recurrence. Further, p53 mutations did not function as independent correlates for prognosis. The co-expression of the studied proto-oncogenes (c-myc, Ha-ras) and the nuclear transcriptional protein (c-fos) functioned as a strong prognostic correlate for recurrence and survival; the effect of individual oncogenes to predict survival was greatest for Ha-ras and c-fos. Immediate or early co-expression of three oncogene proteins in neoplastic transformation endowed cells of invasive carcinoma with an aggressive phenotype. This aggressive phenotype was evident in a small percentage of the studied population (11%) and predicted adverse disease-free and overall survival. These findings suggest that oncogene co-expression possesses significant prognostic and potential therapeutic value; incorporation of this molecular technology into future prospective randomized trials is advisable.

Biomarkers, Tumor↗
PubMed2005

BRAF mutation predicts a poorer clinical prognosis for papillary thyroid cancer.

CONTEXT: Use of BRAF mutation in papillary thyroid cancer (PTC) has the potential to improve risk stratification of this cancer. OBJECTIVE: The objective of the study was to investigate the prognostic value of BRAF mutation in patients with PTC. DESIGN, SETTING, AND SUBJECTS: In a multicenter study of 219 PTC patients, data on their clinicopathological characteristics and clinical courses between 1990 and 2004 were retrospectively collected, and their tumor BRAF mutation status was determined. Associations of BRAF mutation with initial tumor characteristics and subsequent recurrence were analyzed. MAIN OUTCOME MEASURE: Relationships between the BRAF mutation status and clinicopathological outcomes, including recurrence, were measured. RESULTS: We found a significant association between BRAF mutation and extrathyroidal invasion (P < 0.001), lymph node metastasis (P < 0.001), and advanced tumor stage III/IV (P = 0.007) at initial surgery. This association remained significant on multivariate analysis, adjusting for conventional clinicopathological predictors of recurrence excluding the histological PTC subtype, but was lost when the tumor subtype was included in the model. BRAF mutation was also significantly associated with tumor recurrence, 25 vs. 9% with and without mutation, respectively (P = 0.004), during a median of 15 (interquartile range, 3-29) months of follow-up. This association remained significant on multivariate analysis adjusting for conventional clinicopathological predictors of recurrence, even including the PTC subtype (odds ratio, 4.0; 95% confidence interval, 1.1-14.1; P = 0.03). BRAF mutation was even an independent predictor of recurrence in patients with stage I/II disease, 22 vs. 5% with and without BRAF mutation, respectively (P = 0.002). BRAF mutation was also more frequently associated with absence of tumor I-131 avidity and treatment failure of recurrent disease. CONCLUSIONS: In patients with PTC, BRAF mutation is associated with poorer clinicopathological outcomes and independently predicts recurrence. Therefore, BRAF mutation may be a useful molecular marker to assist in risk stratification for patients with PTC.

Adult↗
PubMed2001

Compound heterozygosity for a recurrent 16.5-kb Alu-mediated deletion mutation and single-base-pair substitutions in the ABCC6 gene results in pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder affecting the elastic structures in the skin, eyes, and cardiovascular system, with considerable morbidity and mortality. Recently, mutations in the ABCC6 gene (also referred to as "MRP6" or "eMOAT") encoding multidrug-resistance protein 6 (MRP6), a putative transmembrane ABC transporter protein of unknown function, have been disclosed. Most of the genetic lesions delineated thus far consist of single-base-pair substitutions resulting in nonsense, missense, or splice-site mutations. In this study, we examined four multiplex families with PXE inherited in an autosomal recessive pattern. In each family, the proband was a compound heterozygote for a single-base-pair-substitution mutation and a novel, approximately 16.5-kb deletion mutation spanning the site of the single-base-pair substitution in trans. The deletion mutation was shown to extend from intron 22 to intron 29, resulting in out-of-frame deletion of 1,213 nucleotides from the corresponding mRNA and causing elimination of 505 amino acids from the MRP6 polypeptide. The deletion breakpoints were precisely the same in all four families, which were of different ethnic backgrounds, and haplotype analysis by 13 microsatellite markers suggested that the deletion had occurred independently. Deletion breakpoints within introns 22 and 29 were embedded within AluSx repeat sequences, specifically in a 16-bp segment of DNA, suggesting Alu-mediated homologous recombination as a mechanism.

ATP-Binding Cassette Transporters↗
PubMed2002

Recurrent variable region gene usage and somatic mutation in the human antibody response to the capsular polysaccharide of Streptococcus pneumoniae type 23F.

Combinatorial cloning and expression library analysis were used to isolate human antibody Fab fragments specific for the capsular polysaccharide of Streptococcus pneumoniae serotype 23F. Thirty 23F-specific Fabs were isolated from seven vaccinated donors, and the sequences of the heavy (H)- and light (L)-chain variable regions were determined. All individuals utilized either the Vkappa A23 L chain, the Vkappa L6 L chain, or both chains in forming the 23F-specific combining site. Vkappa A23 L chains paired primarily with VH3-23 H chains. Vkappa L6 L chains were more promiscuous in heavy-chain usage between individuals. Both H and L chains were mutated, primarily in the complementarity-determining regions, compared to their closest germ line counterpart, suggesting a recall response that has undergone affinity maturation. H-chain isotypes were reflective of those found in the serum. Shared somatic modifications demonstrated that immunoglobulin G2 (IgG2) and IgA antibodies arose from the same somatically matured B cell. Our results indicate that the response to the serotype 23F pneumococcal capsular polysaccharide is oligoclonal within the individual, with one or two paratope families accounting for the majority of expressed antibody. We also determined that, in spite of the combinatorial diversity available to the immune system, the 23F-specific response is highly restricted at the population level, with the same two L-chain-determined paratope families recurring in all individuals. Lastly, analysis of the isolated Fabs indicate all have undergone extensive somatic mutation, as well as class switch, maturational events that presumably require the participation of T cells.

Adult↗
PubMed2005

Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis.

Polycythemia vera (PV), essential thrombocythemia (ET), and myeloid metaplasia with myelofibrosis (MMM) are clonal disorders arising from hematopoietic progenitors. An internet-based protocol was used to collect clinical information and biological specimens from patients with these diseases. High-throughput DNA resequencing identified a recurrent somatic missense mutation JAK2V617F in granulocyte DNA samples of 121 of 164 PV patients, of which 41 had homozygous and 80 had heterozygous mutations. Molecular and cytogenetic analyses demonstrated that homozygous mutations were due to duplication of the mutant allele. JAK2V617F was also identified in granulocyte DNA samples from 37 of 115 ET and 16 of 46 MMM patients, but was not observed in 269 normal individuals. In vitro analysis demonstrated that JAK2V617F is a constitutively active tyrosine kinase.

Adult↗
PubMed2002

Desmoplastic infantile astrocytoma and ganglioglioma: a search for genomic characteristics.

In the present study the clinical data, histology, proliferation rate, DNA ploidy status and the results of TP53 mutation analysis and comparative genomic hybridization (CGH) of three typical cases of desmoplastic infantile astrocytoma and ganglioglioma are presented. Postoperative disease-free intervals of 11, 8 and 3 years were recorded and in none of the cases were radiological signs of tumor recurrence. No TP53 mutations (exons 5-8) were found. CGH analysis revealed loss of 8p22-pter in one case, while in another case gain of 13q21 was detected. In the case with the follow-up of 11 years an aneuploid DNA-flow cytogram along with slightly increased MIB-1 labeling index (LI) was found. The results demonstrate little genetic instability in these low-grade lesions. DNA-aneuploidy seems not to be indicative of tumor progression. It is concluded that the genetic aberrations found in desmoplastic infantile ganglioglioma differ from those encountered in common astrocytomas.

Antigens, Nuclear↗