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At least 1,243 records · Page 69Linked to original sources
PubMed2006

[Hereditary pancreatitis caused by a new mutation in the trypsinogen gene. Report of a family].

Hereditary pancreatitis is an uncommon autosomal dominant disease secondary to a mutation normally located in the trypsinogen gene, preventing trypsin deactivation. This mutation translates clinically into recurrent attacks of acute pancreatitis and an increased risk of pancreatic cancer. We report a case of acute hereditary pancreatitis due to a trypsinogen mutation that has previously been described in only one family.

Child↗
PubMed1993

[Expression of mutant P53 gene protein product in human bladder carcinoma].

Expression of P53 protein was detected immunohistochemically in formalin-fixed, paraffin-embedded tissues from 67 patients with bladder carcinoma and 6 normal bladder controls. P53 protein was found positively in 34 of the 67 tumors, whereas no normal bladder controls and no non-cancer tissue cells on tumor sections was stained positively for P53 protein. The percentage of staining for P53 was higher in poorly-differentiated and in invasive tumors than in well and moderately differentiated and in superficial tumors. We also found that P53 positive staining was closely related to tumors recurrence. Hence, the expression of P53 may be used as a tumor marker predicting the histograde, clinical stage and recurrence.

Carcinoma, Transitional Cell↗
PubMed2005

Coincidence of multiple endocrine neoplasia types 1 and 2: mutations in the RET protooncogene and MEN1 tumor suppressor gene in a family presenting with recurrent primary hyperparathyroidism.

CONTEXT: Primary hyperparathyroidism (HPT) presents as a part of inherited syndromes such as multiple endocrine neoplasia (MEN) types 1 and 2. In patients with MEN1, parathyroid hyperplasia or multiple adenomas occur in approximately 90-95%. MEN2A-related HPT is characterized by a mild hypercalcemia, which is mostly asymptomatic. OBJECTIVE: Here we present a family with coexistence of MEN1 gene mutation and RET mutation. RESULTS: Six family members carrying MEN1 gene mutation IVS5 + 1G>A only, one family member with RET mutation Y791F, and three family members with both MEN1 gene and RET mutation were studied. The key to diagnosis was recurrent HPT in a young male carrying RET mutation Y791F, a mutation not likely to give rise to recurrent HPT. CONCLUSION: MEN1 gene mutation and RET codon 791 mutation in the same patient did not affect the typical phenotype of MEN1 or MEN2, and also the course of diseases seems to be unchanged. The reason may be that both mutations, although contributing to tumor pathogenesis, do not interact and induce a worsening of the cancer syndromes.

Adult↗
PubMed1996

p53 gene mutations in radiation-induced thyroid cancer.

Little is known about the role of specific oncogenes and tumor suppressor genes in radiation-induced thyroid cancer (RITC). In thyroid cancer, mutations in the p53 tumor suppressor gene have been largely confined to the more aggressive anaplastic forms. We studied point mutations in the p53 gene in 22 patients exposed in childhood to radiation in the head and neck area who later developed papillary thyroid cancers (RITC). Eighteen thyroid cancer patients without exposure to radiation, selected to match by gender and age the RITC group, were used as the control group. After histological identification, DNA was extracted from paraffin-embedded specimens. Exons 5-8 of p53 were PCR amplified and screened for mutations by single strand conformation polymorphism analysis and cycle sequencing. Four of 22 RITC patients (18%) showed missense point mutations. No missense mutations were found in the cancer control group. The missense mutations in the RITC group occurred at codon 208 in 2 patients, codon 177 in 1, and codon 217 in 1. The mutations were transitions from G to A and C to T. All patients with missense mutations were male and had lymph node involvement. Three of the 4 patients with p53 missense mutations had invasion of the cancer beyond the thyroid capsule compared to 2 of the 17 remaining RITC patients. None of the patients with p53 mutations had distant metastases or recurrence of the tumor. These results suggest that p53 gene point mutations may play a pathogenetic role in some radiation-induced, well differentiated thyroid cancers and in their local spread.

Adolescent↗
PubMed2002

A longitudinal analysis of T-cell epitope-coding regions of hepatitis C virus after liver transplantation.

BACKGROUND: Hepatitis C virus (HCV)-related liver failure is the single leading indication for orthotopic liver transplantation (OLT) worldwide. The mechanisms that underlie the observed differences in natural history of HCV recurrence remain poorly understood. We have previously demonstrated that differential T-cell responses correlate with histologic severity after OLT. We hypothesized that amino acid substitutions within critical T-cell epitopes could lead to increased severity of HCV disease. METHODS: We determined the peptide sequences from sequential serum-derived viral RNA by reverse transcription and direct polymerase chain reaction sequence analysis from 32 HCV genotype 1-infected patients with well-characterized outcomes after liver transplantation. Serum samples were analyzed for HCV sequence the day of OLT and at least one time point post-OLT. To construct evolutionary relationships among the different patient samples, phylogenetic analyses of core and NS3 sequences were performed using a matrix fed into a neighbor-joining tree algorithm. RESULTS: The phylogenetic analyses revealed remarkable conservation within a given individual and no significant differences when comparing patients with severe versus mild recurrence. Accordingly, the synonymous mutation rate was consistently greater than the nonsynonymous substitution rate. The nine epitopic regions analyzed were also preserved so that, with the exception of one patient with mild recurrence, none of the patients demonstrated a shift in viral peptide sequence. CONCLUSIONS: HCV core and NS3 viral peptide sequences are identical before and after OLT in most patients, suggesting that the prevalent sequence is preserved in most cases, and viral variants are competent to establish infection after OLT. Although these results do not support viral mutation as a dominant pathogenic mechanism after OLT, other viral regions need to be analyzed.

Adult↗
PubMed1998

Molecular analysis of the BRCA2 gene in 16 breast/ovarian cancer Spanish families.

The recent isolated gene BRCA2 is responsible for about 45% of familial breast cancer and the majority of male breast cancer families. In order to evaluate the role of inherited BRCA2 mutations in Spanish families, the complete coding sequence of the gene was screened by SSCP/sequencing in 16 high-risk breast/ovarian cancer families. Four mutations were found that cause a premature termination codon. Two of them have been reported elsewhere and one is a novel mutation. In addition we have found seven polymorphisms, two of which have not been previously described. One of the mutations, 936delAAAC was found in two of our high-risk families. Because this mutation is considered as recurrent, we have tried to estimate its frequency in our breast cancer population. A total of 127 moderate- high-risk families were screened for this mutation and it was also found in another high-risk family. All the families carrying the 936delAAAC mutation harboured part of a common haplotype shared by other reported carriers, suggesting a possible founder effect for this mutation.

Adult↗
PubMedDate not supplied

Surgical treatment options in young women with breast cancer.

The diagnosis of breast cancer in young women presents particular challenges in surgical decision making and treatment. These challenges arise from concurrent genetic or other risk factors, potentially more aggressive tumor biology, larger tumor size, and psychosocial factors unique to young women. Local recurrence and survival rates for breast-conserving surgery compared to mastectomy are reviewed and strategies for reducing local recurrence after breast conserving therapy are discussed. Options for incorporating genetic testing and counseling into surgical management are presented. Management of young women with BRCA gene mutations, with a positive family history without a risk gene mutation, and with a history of mantle irradiation for Hodgkin's disease is discussed.

Adult↗
PubMed2006

Genetics of HUS: the impact of MCP, CFH, and IF mutations on clinical presentation, response to treatment, and outcome.

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy with manifestations of hemolytic anemia, thrombocytopenia, and renal impairment. Genetic studies have shown that mutations in complement regulatory proteins predispose to non-Shiga toxin-associated HUS (non-Stx-HUS). We undertook genetic analysis on membrane cofactor protein (MCP), complement factor H (CFH), and factor I (IF) in 156 patients with non-Stx-HUS. Fourteen, 11, and 5 new mutational events were found in MCP, CFH, and IF, respectively. Mutation frequencies were 12.8%, 30.1%, and 4.5% for MCP, CFH, and IF, respectively. MCP mutations resulted in either reduced protein expression or impaired C3b binding capability. MCP-mutated patients had a better prognosis than CFH-mutated and nonmutated patients. In MCP-mutated patients, plasma treatment did not impact the outcome significantly: remission was achieved in around 90% of both plasma-treated and plasma-untreated acute episodes. Kidney transplantation outcome was favorable in patients with MCP mutations, whereas the outcome was poor in patients with CFH and IF mutations due to disease recurrence. This study documents that the presentation, the response to therapy, and the outcome of the disease are influenced by the genotype. Hopefully this will translate into improved management and therapy of patients and will provide the way to design tailored treatments.

Blood Component Transfusion↗
PubMed2006

Neutrophils from patients with TNFRSF1A mutations display resistance to tumor necrosis factor-induced apoptosis: pathogenetic and clinical implications.

OBJECTIVE: To explore tumor necrosis factor (TNF)-induced apoptosis in neutrophils from patients with TNF receptor-associated periodic syndrome (TRAPS) and to correlate the results with the different kinds of TNFRSF1A mutations. METHODS: Two hundred sixty-five patients with clinically suspected inherited autoinflammatory syndrome were screened for mutations of the TNFRSF1A gene. Neutrophils were isolated from heparinized blood by dextran sedimentation and incubated with and without cycloheximide (CHX) and TNFalpha. Cell apoptosis was assessed by human annexin V binding, and caspase 8 activation was assessed by flow cytometry. RESULTS: Twenty-one patients were found to carry a variant of the TNFRSF1A gene: 13 patients had an R92Q substitution, and 8 patients presented other missense substitutions, 1 splicing mutation, and 1 in-frame interstitial deletion. Neutrophil stimulation with TNF and CHX was associated with induction of apoptosis in 12 normal controls and in 10 subjects with the R92Q mutation. Conversely, neutrophils from 8 TRAPS patients with mutations of cysteine or threonine residues or interstitial deletion did not show any induction of apoptosis after stimulation. The incidence of the R92Q mutation among patients with recurrent autoinflammatory syndromes was similar to that observed in the normal population. CONCLUSION: Resistance to TNF-mediated apoptosis is a feature in TRAPS patients who have mutations of cysteine residues or interstitial deletion, and may play a pathogenic role. The R92Q mutation does not appear to be significantly associated with TRAPS.

Adult↗
PubMed2004

[Effect of c-kit gene mutation on prognosis of gastrointestinal stromal tumor].

OBJECTIVE: To evaluate the clinical signification of c-kit gene mutation in gastrointestinal stromal tumor (GIST) and examine whether the presence of mutation of c-kit gene is important as a prognostic factor. METHODS: The c-kit mutation had been detected by PCR-SSCP, DNA sequence, statistical comparison were used for the relationship of c-kit gene mutation and clinical pathology, clinical behavior, recurrence, et al. RESULTS: The presence of c-kit mutation correlated with tumor size, proliferating cell nuclear antigen index, mitotic cell number, presence of necrosis, microscopic invasion to adjacent tissues, recurrence and distant metastasis. The age, sex, location of tumor, cell type, the presence of hemorrhage, and c-kit expression were independently related to the presence of c-kit mutation. CONCLUSIONS: The c-kit gene mutation is an important prognostic factor for GIST.

Adult↗
PubMed1996

Simple and rapid detection of factor V Leiden by allele-specific PCR amplification.

Resistance to activated protein C is the most common hereditary cause for thrombosis and significantly linked to factor V Leiden. In this study, primers were designed to identify the factor V mutation by allele-specific PCR amplification. 126 patients with thromboembolic events were analysed using this technique, PCR-RFLP and direct sequencing. The concordance between these techniques was 100%. In 27 patients a heterozygous factor VGln506 mutation was detected, whereas one patient with recurrent thromboembolism was homozygous for the point mutation. Due to its time- and cost-saving features allele-specific amplification should be considered for screening of factor VGln506.

Alleles↗
PubMed2000

Prospective evaluation of the risk conferred by factor V Leiden and thermolabile methylenetetrahydrofolate reductase polymorphisms in pregnancy.

Factor V (FV) Leiden and thermolabile methylenetetrahydrofolate reductase (MTHFR) are 2 common polymorphisms that have been implicated in vascular thrombosis. We determined whether these mutations predicted an adverse outcome in pregnancy. Second, we looked for an interaction between these 2 mutations in patients with recurrent fetal loss or thrombosis in pregnancy. Primigravid subjects at their booking visit to the National Maternity Hospital (Holles Street, Dublin, Ireland) were screened for the polymorphisms. Thermolabile MTHFR and FV Leiden genotypes were detected by either restriction fragment length polymorphism or heteroduplex capillary chromatography. The carrier frequency of FV Leiden in the screened primigravid population was 2.7% (allele frequency 1.36%), all being heterozygous for the mutation. This value was lower than expected from previous studies in European populations. Forty-nine percent of the screened population (289 of 584) were heterozygous for thermolabile MTHFR, and 10.6% were homozygous (62 of 584). The frequency of the 2 polymorphisms was no higher in those who subsequently developed preeclampsia (n=12) or intrauterine growth retardation (n=9), and none of the screened population developed thrombosis. However, the frequency of FV Leiden was higher in patients who subsequently miscarried after the first trimester of pregnancy (allele frequency of 5.5%, P=0.0356). Among those positive for FV Leiden, 3 of 27 miscarried, compared with 24 of 572 of FV Leiden-negative patients (11% versus 4.2%). No interaction was found between the 2 mutations in the control or patient populations. In patients with a prior history of venous thrombosis, the carrier rate of FV Leiden was increased (4 of 33, allele frequency of 7.6%, P=0. 0115). In contrast, the carrier frequency for thermolabile MTHFR was no higher, and there was no interaction between the 2 mutations. Neither mutation occurred at a significantly higher frequency in patients with a prior history of recurrent fetal loss. In conclusion, FV Leiden is a risk factor for thrombosis in pregnancy and possibly for second-trimester miscarriage independent of thermolabile MTHFR. However, prospective analysis suggests that the risk conferred by FV Leiden is low in a primigravid population. The thermolabile MTHFR genotype was not implicated in any adverse outcome.

Abortion, Habitual↗
PubMed2004

Genetically altered fields as origin of locally recurrent head and neck cancer: a retrospective study.

PURPOSE: Surgeons treating patients with head and neck squamous cell carcinoma (HNSCC) rely heavily on histology to decide whether the resection margins are tumor free and subsequent adjuvant treatments can be omitted. However, despite the presence of tumor-free margins, 10-30% of HNSCC patients still develop a locally recurrent tumor. Evidence is available that recurrent cancer develops from either (a). outgrowth of a relatively small number of tumor cells that have not been detected by the pathologist or (b). a precursor lesion in which additional genetic alterations have led again to invasive cancer. EXPERIMENTAL DESIGN: In a retrospective study on 13 HNSCC cases, we analyzed the primary tumor, its surrounding histologically tumor-free resection margins, and local recurrences for loss of heterozygosity (22 microsatellite markers on 6 chromosomes) and TP53 mutations to determine the origin of the recurrent cancer. RESULTS: A precursor lesion was absent in 5 of 13 (39%) cases, and the genetic similarity of the primary and recurrent cancer was high, providing evidence that residual cancer cells were the origin of recurrence. For the remaining eight cases (61%) a genetically related precursor lesion (field) was detected, and for five of these cases, evidence was found that both the primary and recurrent carcinoma originated from this field. The remaining three cases were less conclusive. CONCLUSIONS: This study explains the pathobiology of locally recurrent HNSCC in patients with histologically tumor-free resection margins and indicates that the development of novel therapies to decrease the local recurrence rates in HNSCC should not only be focused on eradicating residual cancer cells but also on the precursor lesions that are left behind.

Adult↗
PubMed2003

Recurrent deep-vein thrombosis based on homozygous factor V Leiden mutation acquired after liver transplantation.

Several genetic liver diseases can be treated by liver transplantation (LT). However, some genetic defects also may be acquired by this procedure. We describe a patient who developed recurrent deep-vein thromboses after LT for hepatitis C virus-associated hepatocellular carcinoma on the basis of a homozygous Leiden mutation of the factor V gene in the donor liver. Liver donors with a history of venous thrombosis should be screened for the presence of activated protein C (APC) resistance. In addition, we recommend looking for APC resistance in liver recipients who develop venous thromboembolic disease in the post-LT course. Molecular analysis of donor tissue may be necessary to make a definite diagnosis of factor V Leiden mutation in these patients. As a consequence, intensified postoperative thromboprophylaxis or lifelong anticoagulant therapy may be necessary if this thrombophilic gene defect is detected.

Activated Protein C Resistance↗
PubMed2003

Analysis of haemophilia B database and strategies for identification of common point mutations in the factor IX gene.

Haemophilia B is an X-linked recessively inherited bleeding disorder caused by heterogeneous mutations spanning the entire factor IX gene. As spontaneous germ-line mutations are known to occur mostly at CpG dinucleotides in the FIX gene, control of the disease would require continuous carrier detection and mutation screening. Identification of point mutations, the most common type of mutation in FIX gene, is more challenging compared with deletion and insertion mutations. We examined the haemophilia B database to identify specific nucleotides in the FIX gene that are mutated in relatively large number of patients and the variability (if any) in the mutational hotspots at CpG dinucleotides. It was found that while mutations responsible to account for all 2348 haemophilia B patients covered 20% of the FIX cDNA, only 1% of the cDNA involving mostly CpG dinucleotides accounted for mutation in 42.41% of the patient pool. Thus, only 27 nucleotides need to be investigated to identify the common point mutations, among which 15 are predicted to undergo change in restriction sites on mutation. It is interesting to note that seven nucleotides occurring in CpG dinucleotides do not have any reported mutation despite each of those being predicted to harbour mutation as a result of transition and having mutations recorded in the database for the neighbouring nucleotides. Strikingly large number of mutation in codon 296 causing T to M change in catalytic domain originally proposed to be the result of the founder effect also contains largest number of haplotype suggesting recurrence of de novo mutation.

DNA, Complementary↗