Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “mutation analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed2003

Mutation analysis of AMP-activated protein kinase subunits in inherited cardiomyopathies: implications for kinase function and disease pathogenesis.

Familial hypertrophic cardiomyopathy (HCM) has been defined as a disease of the cardiac sarcomere, although sarcomeric protein mutations are not found in one third of cases. We have recently shown that HCM associated with Wolff-Parkinson-White syndrome (WPW) and conduction disease can be caused by mutations in PRKAG2, which encodes the gamma2 subunit of AMPK, an enzyme central to cellular energy homeostasis. AMPK is a heterotrimer composed of one catalytic subunit (alpha) and two regulatory subunits (beta and gamma). Seven known genes encode the subunit isoforms (alpha1, alpha2, beta1, beta2, gamma1, gamma2, gamma3) and all are expressed in the heart. To better understand the role of AMPK mutations in HCM/WPW and other inherited cardiomyophathies, all 7 subunit genes were screened for mutations in a panel of probands: 3 with HCM/WPW, 4 with DCM/WPW, 38 with HCM alone (in whom contractile protein mutations had not been found) and 13 with DCM alone. In total, 73 amplimers were screened in the 58 probands and a number of polymorphisms, including non-conservative substitutions, were identified. However, no further disease-causing mutations were found in any AMPK subunit gene. These results indicate that HCM with WPW is a distinct, but genetically heterogeneous, condition caused by mutations in PRKAG2 and in an unknown gene or genes, not involved in the AMPK complex. Mutations in PRKAG2 appear to specifically cause HCM with WPW and conduction disease, and not other inherited cardiomyopathies. As deleterious alleles were not found in other AMPK subunit isoforms, the mutations affecting PRKAG2 are likely to confer a specific alteration of AMPK function of particular importance in the myocardium.

AMP-Activated Protein Kinases↗
PubMed1994

Direct mutational analysis in a family with hereditary non-polyposis colorectal cancer.

BACKGROUND: It is now known that a proportion of cases of hereditary non-polyposis colorectal cancer (HNPCC) is caused by mutations in the human homologue of the yeast DNA mismatch repair gene MSH2. A proline to leucine change due to a C to T transition in codon 622 of hMSH2 has been identified in a large HNPCC family of over 240 individuals. AIM: To develop an assay to detect the family-specific mutation and apply the findings to genetic screening. METHODS: The C to T change in codon 622 creates a new Mae I site (CTAG) allowing a simple, non-radioactive assay to be developed in order to detect this mutation. The assay was applied to affected members of the family and their first degree relatives (siblings and offspring) between the ages of 17 and 77 years, a total of 75 subjects within two generations (IV and V). RESULTS: 13/13 (100%) subjects with cancer were mutation positive, 7/7 (100%) elderly subjects from generation IV and with no evidence of cancer were mutation negative, 23/57 (40%) subjects from generation V were mutation positive and 0/50 (100%) unrelated subjects were mutation negative. Following the demonstration of perfect segregation of the disease with the mutation, family members were invited to receive the results of the test. Sixty-three (84%) responded within six weeks of receiving the invitation. Genetic screening and counselling members of HNPCC families was perceived as beneficial overall, allowing non-carriers of the mutant gene (as well as their descendants) to be removed from a programme of colonoscopic surveillance.

Adolescent↗
PubMed2001

Mutational analysis of N-ras, p53, p16INK4a, p14ARF and CDK4 genes in primary human malignant mesotheliomas.

Nineteen specimens from primary human malignant mesotheliomas obtained from 19 patients were screened for activating point mutations in the oncogenes N-ras and CDK4 by combined RFLP-PCR/SSCP analysis. In addition, all tumours were screened for deletions and point mutations in the tumour suppressor genes p53, p16INK4a (CDKN2A) and p14ARF (exon-1beta) by combined multiplex-PCR/SSCP analysis. No mutations were found in N-ras, p53 and CDK4. Three tumours displayed homozygous deletion (co-deletion of exons 1, 2 and 3) of p16INK4a. One of them displayed additional homozygous deletion of p14ARF (exon-1beta). Two silent point mutations and 2 polymorphisms were found in p16INK4a in 3 tumours. Our preliminary data indicate that disarrangement of the Rb1 pathway may be involved in mesothelioma formation.

Adult↗
PubMed2004

Ki-ras mutational analysis in rat follicular-cell proliferative lesions of the thyroid gland induced by radioactive iodine and potassium perchlorate.

Although in both human and experimental pathology ras mutations have been related to the origin and progression of follicular-cell tumours, reports differ considerably with respect to the frequency of such mutations. The present paper reports, using direct sequencing, the incidence of Ki-ras mutations (codons 12 and 13) in follicular-cell carcinomas of the thyroid gland in Wistar rats induced by administration of radioactive iodine and potassium perchlorate. Direct sequencing revealed no mutations in the amplified gene segment of any of the 72 carcinoma samples studied. This absence of mutations agrees with some and is in sharp contrast with other previous reports in the literature, both for experimental animals and in studies of human thyroid follicular-cell carcinoma. Our results suggest that Ki-ras activation via mutations at codons 12 and 13 is neither a constant event nor an early event in the development of rat thyroid follicular-cell carcinoma.

Adenocarcinoma, Follicular↗
PubMed1991

Mutational analysis of the functional domains of yeast K1 killer toxin.

To determine the functional domains of K1 killer toxin, we analyzed the phenotypes of a set of mutations throughout regions encoding the alpha- and beta-toxin subunits that allow secretion of mutant toxins. A range of techniques have been used to examine the ability of mutant toxins to bind to beta-glucan cell wall receptor and to form lethal ion channels. Our results indicate that both the alpha and beta subunits are involved in beta-glucan receptor binding. Defects in ion channel formation and toxin immunity are confined to the hydrophobic alpha subunit of the toxin.

Base Sequence↗
PubMed1992

Cloning and mutational analysis of SRY.

A candidate for the male sex-determining gene has recently been isolated. This sex-determining gene (SRY) has been found to be mutated in some individuals with failed testis development, and, in mouse transgenesis, the SRY murine homologue (Sry) causes female-to-male sex reversal. The cloning of SRY should facilitate the characterisation of other genes in the testis-determining pathway and provide information on the mechanism of mammalian developmental decisions.

Animals↗
PubMed2000

BRCA1 and BRCA2 mutation analysis of 208 Ashkenazi Jewish women with ovarian cancer.

Ovarian cancer is a component of the autosomal-dominant hereditary breast-ovarian cancer syndrome and may be due to a mutation in either the BRCA1 or BRCA2 genes. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in the Ashkenazi Jewish population. One of these three mutations is present in approximately 2% of the Jewish population. Each mutation is associated with an increased risk of ovarian cancer, and it is expected that a significant proportion of Jewish women with ovarian cancer will carry one of these mutations. To estimate the proportion of ovarian cancers attributable to founding mutations in BRCA1 and BRCA2 in the Jewish population and the familial cancer risks associated with each, we interviewed 213 Jewish women with ovarian cancer at 11 medical centers in North America and Israel and offered these women genetic testing for the three founder mutations. To establish the presence of nonfounder mutations in this population, we also completed the protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2. We obtained a detailed family history on all women we studied who had cancer and on a control population of 386 Ashkenazi Jewish women without ovarian or breast cancer. A founder mutation was present in 41.3% of the women we studied. The cumulative incidence of ovarian cancer to age 75 years was found to be 6.3% for female first-degree relatives of the patients with ovarian cancer, compared with 2.0% for the female relatives of healthy controls (relative risk 3.2; 95% CI 1.5-6.8; P=.002). The relative risk to age 75 years for breast cancer among the female first-degree relatives was 2.0 (95% CI 1.4-3.0; P=.0001). Only one nonfounder mutation was identified (in this instance, in a woman of mixed ancestry), and the three founding mutations accounted for most of the observed excess risk of ovarian and breast cancer in relatives.

Adult↗
PubMed1998

Mutation analysis of LMX1B gene in nail-patella syndrome patients.

Nail-patella syndrome (NPS), a pleiotropic disorder exhibiting autosomal dominant inheritance, has been studied for >100 years. Recent evidence shows that NPS is the result of mutations in the LIM-homeodomain gene LMX1B. To determine whether specific LMX1B mutations are associated with different aspects of the NPS phenotype, we screened a cohort of 41 NPS families for LMX1B mutations. A total of 25 mutations were identified in 37 families. The nature of the mutations supports the hypothesis that NPS is the result of haploinsufficiency for LMX1B. There was no evidence of correlation between aspects of the NPS phenotype and specific mutations.

Animals↗
PubMed2003

Mutation analysis of the Smad3 gene in human osteoarthritis.

Osteoarthritis (OA) is the most common joint disease worldwide. Recent studies have shown that targeted disruption of Smad3 in mouse results in OA. To reveal the possible association between the Smad3 gene mutation and human OA, we employed polymerase chain reaction-single strand conformation polymorphism and sequencing to screen mutations in all nine exons of the Smad3 gene in 32 patients with knee OA and 50 patients with only bone fracture. A missense mutation of the Smad3 gene was found in one patient. The single base mutation located in the linker region of the SMAD3 protein was A --> T change in the position 2 of codon 197 and resulted in an asparagine to isoleucine amino-acid substitution. The expressions of matrix metalloproteinase 2 (MMP-2) and MMP-9 in sera of the patient carrying the mutation were higher than other OA patients and controls. This is the first report showing that the Smad3 gene mutations could be associated with the pathogenesis of human OA.

DNA Mutational Analysis↗
PubMed2002

Mutational analysis reveals a role for the C terminus of the proteasome subunit Rpt4p in spindle pole body duplication in Saccharomyces cerevisiae.

The ubiquitin/proteasome pathway plays a key role in regulating cell cycle progression. Previously, we reported that a conditional mutation in the Saccharomyces cerevisiae gene RPT4/PCS1, which encodes one of six ATPases in the proteasome 19S cap complex/regulatory particle (RP), causes failure of spindle pole body (SPB) duplication. To improve our understanding of Rpt4p, we created 58 new mutations, 53 of which convert clustered, charged residues to alanine. Virtually all mutations that affect the N-terminal region, which contains a putative nuclear localization signal and coiled-coil motif, result in a wild-type phenotype. Nine mutations that affect the central ATPase domain and the C-terminal region confer recessive lethality. The two conditional mutations identified, rpt4-145 and rpt4-150, affect the C terminus. After shift to high temperature, these mutations generally cause cells to progress slowly through the first cell cycle and to arrest in the second cycle with large buds, a G2 content of DNA, and monopolar spindles, although this phenotype can vary depending on the medium. Additionally, we describe a genetic interaction between RPT4 and the naturally polymorphic gene SSD1, which in wild-type form modifies the rpt4-145 phenotype such that cells arrest in G2 of the first cycle with complete bipolar spindles.

Adenosine Triphosphatases↗
PubMed2001

Mutation analysis of the entire replicated portion of PKD1 using genomic DNA samples.

The replicated portion of PKD1, which comprises nearly 70% of the length of the gene, is predicted to harbor at least 85% of the mutations present in affected autosomal dominant polycystic kidney disease type 1 pedigrees. The relative paucity of reported mutations involving this segment is attributable to the significant technical challenges posed by the genomic structure of the gene. Previous genomic DNA-based strategies were unable to evaluate exons 1 and 22 and relied on the use of 10- to 13-kb PCR products. In this report, a set of six novel primer pair combinations, which can be used with previously reported reagents to analyze all of the exons in the replicated region (exons 1 to 34), are described. No product is greater than 5.8 kb in length, and various primer combinations can be used to reduce this length in half. Using this approach, two new pathogenic mutations, four novel disease-associated missense substitutions, and six new normal variants were identified. These new reagents should prove useful to investigators interested in performing DNA testing for this disorder.

Base Sequence↗
PubMed2002

Mutation analysis of the STK11/LKB1 gene and clinical characteristics of an Australian series of Peutz-Jeghers syndrome patients.

Peutz-Jeghers syndrome (PJS) is a rare cancer predisposition, which is characterized by the presence of hamartomatous polyposis and mucocutaneous pigmentation. A significant proportion of both familial and sporadic forms of this disorder are associated with mutations in the STK11 (serine/threonine kinase 11)/LKB1 gene. In this report we present a series of Australian PJS cases, which suggest that mutations in the STK11 gene do not account for many families or patients without a family history. The most likely explanation is either the presence of another susceptibility gene or genetic mosaicism in the non-familial patients.

AMP-Activated Protein Kinase Kinases↗
PubMed1999

Mutational analysis of the tau gene in progressive supranuclear palsy.

OBJECTIVE: To identify genetic mutations in the coding regions and the splice-donor sites of the tau gene on chromosome 17q in individuals with progressive supranuclear palsy (PSP). BACKGROUND: Several studies provide evidence for linkage disequilibrium between a PSP disease gene and allelic variants of the tau gene. However, a causative mutation has not been identified. METHODS: We designed a study to search for genetic mutations in 15 coding regions of the tau gene including the splice-donor sites in 22 patients with PSP by comparing the mobility shifts on single-strand conformation analysis with those of age-matched controls. Fragments with altered migration were sequenced directly and compared for differences in nucleotide composition. Restriction enzyme digests were used to confirm single base-pair substitutions. RESULTS: Significant differences in mobility shifts were found in exons 1, 4A, and 8 between affected individuals and age-matched controls. All individuals with PSP had a common extended haplotype characterized by a homozygous polymorphism in the 5' splice site untranslated region of exon 1, two missense mutations in exon 4A (Asp285Asn, Ala289Val), and a nonsense mutation in the 5' splice site of exon 8. CONCLUSIONS: This study demonstrates that 22 unrelated progressive supranuclear palsy (PSP) patients have four identical sequence variants within the tau gene that are not present in 24 age-matched controls. Although the functional significance of these results on tau protein expression is unknown, the presence of this "susceptibility" haplotype in individuals may place them at risk for developing PSP.

Aged↗
PubMed1998

Mutation analysis in the iduronate-2-sulphatase gene in 43 Japanese patients with mucopolysaccharidosis type II (Hunter disease).

Our series of studies on Hunter disease in Japanese patients showed allelic heterogeneity of IDS gene mutations, genotype/phenotype correlation and racial differences in distribution of mutations. Twenty-five different small mutations have been characterized. Small mutations in the Japanese population are widely distributed through the IDS gene, although some mutations were unevenly concentrated on exon 5 (28%) and on exon 9 (24%). Mutations were seen at the same codon 468 in exon 9 in 5 patients. These findings are in good agreement with data on other ethnic groups. Two unique mutations linked to a severe phenotype were apparently associated with aberrant splicings; one was a point mutation within exon 3 (P86L), partially activating a cryptic splice acceptor site at 28 bp downstream from the mutation site within exon 3 and producing a 44-base truncated mRNA, and the other was a point mutation at the consensus sequence of the splice donor site of intron 2, causing exon 2 skipping.

Base Sequence↗
PubMed2004

Mutational analysis of the ATP2A2 gene in two Darier disease families with intrafamilial variability.

BACKGROUND: Darier disease (DD), an autosomal dominant genodermatosis characterized by warty papules and plaques over seborrhoeic areas, is caused by mutations in the ATP2A2 gene, which encodes the sarco/endoplasmic reticulum Ca(2+) ATPase type 2 isoform (SERCA2). While markedly different clinical severity within DD-affected family members is known, the pathomechanism has not been elucidated. OBJECTIVES: Based on the hypothesis that multiple ATP2A2 mutations might contribute to the pathomechanism, we have analysed two DD families in which the clinical severity differs markedly within a single pedigree, and, as controls, eight DD families without differing clinical severity. METHODS: All the exons and intron-exon borders of ATP2A2 were directly sequenced from the genomic DNA extracted from all the subjects. RESULTS: We identified the heterozygous mutations, G233R in pedigree 1 and C318R in pedigree 2, respectively, whereas no other ATP2A2 mutations in any of severely affected individuals were found. In eight DD pedigrees as control, we have found M1V, N39D, L180R, A838P and 2170 insertion G in each of five pedigrees, but no mutation was found in three DD pedigrees. CONCLUSIONS: Our results together with previous data indicate that the distribution of mutations is scattered over the entire ATP2A2 without any, as yet, discernible 'hotspots'. The mutations in pedigrees 1 and 2 with intrafamiliar clinical differences occurred around the Ca(2+)-binding sites on SERCA2, which might be associated with differences in clinical severity. These variations in ATP2A2 mutations alone cannot account for the clinical heterogeneity within DD pedigrees.

Adolescent↗
PubMed1997

Mutation analysis of IL2RG in human X-linked severe combined immunodeficiency.

Severe combined immunodeficiency (SCID) is a syndrome of profoundly impaired cellular and humoral immunity. In humans, SCID is most commonly caused by mutations in the X-linked gene IL2RG, which encodes the common gamma chain, gamma c, of the leukocyte receptors for interleukin-2 and multiple other cytokines. To investigate the frequency and variety of IL2RG mutations that cause SCID, we analyzed DNA, RNA, and B-cell lines from a total of 103 unrelated SCID-affected males and their relatives using a combination of molecular and immunologic techniques. Sixty-two different mutations spanning all eight IL2RG exons were found in 87 cases, making possible correlations between mutation type and functional consequences. Although skewed maternal X chromosome inactivation, single-strand conformation polymorphism, mRNA expression, and cell surface staining with anti-gamma c antibodies were all helpful in establishing IL2RG defects as the cause of SCID, only dideoxy fingerprinting and DNA sequence determination each detected 100% of the IL2RG mutations in our series. Abnormal gamma c chains may be expressed in the lymphocytes of as many as two thirds of patients with X-linked SCID. Specific mutation diagnosis thus remains technically challenging, but it is important for genetic counseling and perhaps for helping to select appropriate subjects for retroviral gene therapy trials, This is a US government work. There are no restrictions on its use.

DNA Fingerprinting↗
PubMed1995

Mutational analysis of CDKN2 (CDK4I/MTS1) gene in tissues and cell lines of human prostate cancer.

To study mutation of the CDKN2 gene in prostate cancer, samples from 51 Japanese patients and four human prostate cancer cell lines were examined by single-strand conformation polymorphism analysis and direct sequencing. Only one out of 51 (2%) patients revealed a mutation, which was a 24 bp deletion from the 5'-untranslated region to codon 3, resulting in loss of the initiation site. One of the four cell lines revealed a missense mutation, a GAC-->TAC (Asp-->Tyr) at codon 84. These results indicate that mutation of the CDKN2 gene is rare in prostate cancer and thus does not contribute significantly to the pathogenesis of human prostate cancer. Prostate cancer cell lines may acquire more frequent abnormality of the CDKN2 gene than tumor tissues.

Base Sequence↗