SEARCH · Search PubMed

Results for “mutational screening”

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.

SourceResearch connectionFrom yearThrough year

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

At least 595 records · Page 33Linked to original sources

PubMed1992

A completed screen for mutations of the rhodopsin gene in a panel of patients with autosomal dominant retinitis pigmentosa.

Recently it has been demonstrated that some families with autosomal dominant retinitis pigmentosa (adRP) have mutations in the rhodopsin gene while others do not. Previously we have identified six such mutations in seven adRP families in this laboratory, one of which was previously described in US patients. We now present a completed screen of the rhodopsin gene in a panel of 39 adRP families, by a rapid screening technique which will be of use for routine diagnosis. Nine different mutations were ultimately found, in a total of twelve of the 39 families. These include the six previously identified mutations, in codons 68-71, 190, 211, 255, 296 and 347, two new ones in codons 53 and 106, and another mutation first identified in a single US patient, in codon 58. Thus approximately 30% of adRP families have 'Rhodopsin RP' while the remainder probably have a defect elsewhere in the genome. Of those families in which rhodopsin mutations have been found, four have been classified D type, three as sectorial RP and the remainder are of uncertain classification. All families excluded from chromosome 3q by linkage have been classified R type. These data suggest a correlation between clinical sub-classification and the underlying rhodopsin/non-rhodopsin heterogeneity.

Amino Acid Sequence↗

PubMed1999

Bilateral Wilms tumor in a boy with severe hypospadias and cryptochidism due to a heterozygous mutation in the WT1 gene.

Mutations in the WT1 gene causing Wilms tumors were first reported in WAGR syndrome (Wilms tumor, Aniridia, Genitourinary malformation, mental Retardation) and Denys Drash syndrome (pseudohermaphroditism, Wilms tumor, nephropathy), but only in a few patients with hypospadias and cryptorchidism without other signs of Denys Drash (DDS) or WAGR syndrome WT1 mutations were identified. We report a boy, who was born in 1989 with hypospadias and bilateral cryptorchidism. Previous karyotyping and endocrine studies had ruled out any known cause of male pseudohermaphroditism. Subsequently, he developed a bilateral Wilms tumor, which was detected by palpation at the age of 15 months during a routine visit by the general pediatrician. Because of its extensive size, surgery and chemotherapy were needed for treatment. Analysis of the WT1 gene was performed 5 y after diagnosis and revealed a C to T transition in one allele generating a stop codon at codon 362 and subsequently leading to a truncated protein with loss of its ability to bind to DNA. No signs of DDS or WAGR syndrome are present in the boy. The work up of this patient and the so far known few comparable cases from the literature lead to the conclusion that in newborns with severe urogenital malformations not due to known chromosomal or endocrine disorders mutational screening of the WT1 gene should be performed, to evaluate the high risk of developing a Wilms tumor. We favor mutational screening in these patients as an easy tool for investigation, because in the future it will probably decrease the necessity of frequent control visits in patients without a WT1 mutation.

Base Sequence↗

PubMed2004

Screening for mutations related to atovaquone/proguanil resistance in treatment failures and other imported isolates of Plasmodium falciparum in Europe.

BACKGROUND: Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. METHODS: We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. RESULTS: We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. CONCLUSIONS: Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient pool.

Adolescent↗

PubMed2000

Development of a rapid assay for screening point mutations associated with quinolone resistance in the Pseudomonas aeruginosa parC gene.

To detect quinolone resistance-associated mutations within the Ser-80 and Glu-84 codons of the Pseudomonas aeruginosa parC gene, we developed a rapid and simple assay based on polymerase chain reaction (PCR) amplification of the region of the parC gene containing the mutation sites and digestion of the PCR products with a restriction enzyme. The mutations generating alterations at Ser-80 and Glu-84 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Among 22 clinical isolates tested by this assay, mutations at the Ser-80 and Glu-84 codons were detected in all 10 isolates in which the presence of the mutations had been confirmed previously by DNA sequencing. This rapid and simple assay could be a useful screening device for genetic alterations associated with resistance to quinolones in the P. aeruginosa parC gene.

4-Quinolones↗

PubMed2005

A genetic screen for mutations that affect cranial nerve development in the mouse.

Cranial motor and sensory nerves arise stereotypically in the embryonic hindbrain, act as sensitive indicators of general and region-specific neuronal development, and are directly or indirectly affected in many human disorders, particularly craniofacial syndromes. The molecular genetic hierarchies that regulate cranial nerve development are mostly unknown. Here, we describe the first mouse genetic screen that has used direct immunohistochemical visualization methods to systematically identify genetic loci required for cranial nerve development. After screening 40 pedigrees, we recovered seven new neurodevelopmental mutations. Two mutations model human genetic syndromes. Mutation 7-1 causes facial nerve anomalies and a reduced lower jaw, and is located in a region of conserved synteny with an interval associated with the micrognathia and mental retardation of human cri-du-chat syndrome. Mutation 22-1 is in the Pax3 gene and, thus, models human Waardenburg syndrome. Three mutations cause global axon guidance deficits: one interferes with initial motor axon extension from the neural tube, another causes overall axon defasciculation, and the third affects general choice point selection. Another two mutations affect the oculomotor nerve specifically. Oculomotor nerve development, which is disrupted by six mutations, appears particularly sensitive to genetic perturbations. Phenotypic comparisons of these mutants identifies a "transition zone" that oculomotor axons enter after initial outgrowth and in which new factors govern additional progress. The number of interesting neurodevelopmental mutants revealed by this small-scale screen underscores the promise of similar focused genetic screens to contribute significantly to our understanding of cranial nerve development and human craniofacial syndromes.

Amino Acid Sequence↗

PubMed2005

Clinical, genetic, and biochemical findings in two siblings with Papillon-Lefèvre Syndrome.

BACKGROUND: Papillon-Lefèvre Syndrome (PLS) is an autosomal recessive disease characterized by palmoplantar hyperkeratosis and severe periodontitis affecting both primary and secondary dentitions. Cathepsin C (CTSC) gene mutations are etiologic for PLS. The resultant loss of CTSC function is responsible for the severe periodontal destruction seen clinically. METHODS: A 4-year-old female (case 1) and her 10-year-old sister (case 2) presented with palmoplantar skin lesions, tooth mobility, and advanced periodontitis. Based on clinical findings, the cases were diagnosed with PLS. Mutational screening of the CTSC gene was conducted for the cases, and their clinically unaffected parents and brother. Biochemical analysis was performed for CTSC, cathepsin G (CTSG), and elastase activity in neutrophils for all members of the nuclear family. The initial treatment included oral hygiene instruction, scaling and root planing, and systemic amoxicillin-metronidazole therapy. RESULTS: CTSC mutational screening identified a c.415G>A transition mutation. In the homozygous state, this mutation was associated with an almost complete loss of activity of CTSC, CTSG, and elastase. Although monthly visits, including scaling, polishing, and 0.2% chlorhexidine digluconate irrigation were performed to stabilize the periodontal condition, case 1 lost all her primary teeth. In case 2, some of the permanent teeth could be maintained. CONCLUSIONS: This report describes two siblings with a cathepsin C gene mutation that is associated with the inactivity of cathepsin C and several neutrophil serine proteases. The failure of patients to respond to periodontal treatment is discussed in the context of these biological findings.

Adenine↗

PubMed2006

Prothrombin gene 20209 C >T along with the first description of a homozygous polymorphism at the 3' downstream region +4 C >T in the Turkish population.

Mutation screening studies related with thrombosis revealed that prothrombin 20210A allele of the prothrombin gene leads to an increase in plasma prothrombin levels. The G20210A mutation screening has become a routine analysis in patients with thrombosis. For the detection of the mutation, several molecular techniques have been defined. Real-time polymerase chain reaction is an easy and feasible way to monitor this mutation according to the melting point analysis. Here we report a different pattern in the LightCycler melting point analysis of 2 patients with thrombosis. DNA sequencing of the prothrombin gene showed that these patients with an atypical melting point profile carry a 20209 C >T mutation along with a novel homozygous polymorphism at the 3' downstream region, +4 C >T.

Adolescent↗

PubMed2005

NMD microarray analysis for rapid genome-wide screen of mutated genes in cancer.

Gene mutations play a critical role in cancer development and progression, and their identification offers possibilities for accurate diagnostics and therapeutic targeting. Finding genes undergoing mutations is challenging and slow, even in the post-genomic era. A new approach was recently developed by Noensie and Dietz to prioritize and focus the search, making use of nonsense-mediated mRNA decay (NMD) inhibition and microarray analysis (NMD microarrays) in the identification of transcripts containing nonsense mutations. We combined NMD microarrays with array-based CGH (comparative genomic hybridization) in order to identify inactivation of tumor suppressor genes in cancer. Such a "mutatomics" screening of prostate cancer cell lines led to the identification of inactivating mutations in the EPHB2 gene. Up to 8% of metastatic uncultured prostate cancers also showed mutations of this gene whose loss of function may confer loss of tissue architecture. NMD microarray analysis could turn out to be a powerful research method to identify novel mutated genes in cancer cell lines, providing targets that could then be further investigated for their clinical relevance and therapeutic potential.

Animals↗

PubMed2003

Designing and implementing quality control for multi-center screening of mutations in the ATM gene among women with breast cancer.

Epidemiologic studies of breast and other cancers are increasingly turning toward large, multi-center designs in order to obtain adequate power to detect low-penetrance susceptibility alleles. The size of such studies often makes it necessary to distribute the genetic screening efforts to multiple sites. Careful standardization of screening methodology and quality control across sites is required for such multi-center screening designs to be efficient. In this report, we illustrate our approach to these challenges in the context of the WECARE (Women's Environment, Cancer and Radiation Epidemiology) Study, a multi-center population-based genetic epidemiologic study of women with unilateral and bilateral breast cancer. We provide optimized conditions for screening the ataxia-telangiectasia gene (ATM) for variation by denaturing high-performance liquid chromatography (DHPLC) and describe the results of two independent quality control studies at four international centers employing these conditions. Finally, we report novel mutations in the ATM gene identified both in patients with ataxia-telangiectasia and in patients with unilateral or bilateral breast cancer.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2001

Denaturing gradient gel electrophoresis screening for mutations in the hereditary hyperferritinaemia cataract syndrome.

Hereditary hyperferritinaemia cataract syndrome (HHCS) is characterized by hyperferritinaemia without iron overload. It is essential to differentiate true iron accumulation from HHCS as these patients rapidly develop iron-deficient anaemia when subjected to phlebotomies. The diagnosis of HHCS relies on the identification of point mutations or deletions present in the iron-responsive element of the first exon of the L-ferritin gene. However, many samples referred for diagnosis of putative HHCS are normal. To avoid unnecessary DNA sequencing, we have developed a diagnosis strategy based on the screening of the target DNA region by denaturing gradient gel electrophoresis. This method enabled the accurate identification of 11 different previously known mutations. This strategy will be of interest for family studies or for the screening of large series of patients.

5' Untranslated Regions↗

PubMed2001

Spectrum of mutations in the CFTR gene of patients with classical and atypical forms of cystic fibrosis from southwestern Sweden: identification of 12 novel mutations.

Cystic fibrosis (CF) is caused by mutations in the CFTR gene. The spectrum of CFTR mutations varies between populations and depends on different factors, such as ethnic background and geographical location. The extensive CFTR mutation screening of 129 patients with classical or atypical CF from the south-western region of Sweden revealed the presence of 37 CFTR mutations, including 12 novel alleles. The overall mutation detection rate in this study population was 92%, the highest among all tested regions in Sweden. Eight mutations with a frequency above 1% (DeltaF508, 394delTT, R117C, 3659delC, E60X, 1112delT, R764X, and 621 + 1G --> T) accounted for 78% of CF chromosomes and have been recommended for inclusion in the CFTR mutation screening panel for molecular diagnosis of CF in this region. The multiple occurrence of specific CFTR alleles less common than the predominant DeltaF508 mutation (394delTT, R117C, 3659delC) allowed for genotype-phenotype comparisons and revealed consistent relationships between these mutations and disease severity.

Adult↗

PubMed2005

A novel mutation of COL2A1 resulting in dominantly inherited rhegmatogenous retinal detachment.

PURPOSE: To determine the molecular defect in a family with autosomal dominant rhegmatogenous retinal detachment (DRRD), and to investigate missplicing as a possible phenotypic modifier of mutations in COL2A1. METHODS: Clinical examination of the family and linkage analysis using markers flanking COL2A1 and COL11A1, the known loci for Stickler syndrome; mutation screening of COL2A1; construction of splicing reporter minigenes and transfection into cultured cells; and RT-PCR analysis of reporter specific transcripts. RESULTS: A family with DRRD showed no systemic clinical signs (skeletal, orofacial, or auditory) usually associated with Stickler syndrome. Linkage analysis excluded COL11A1 as the disease locus but could not exclude COL2A1. Mutation screening of COL2A1 identified a novel G118R mutation in type II collagen. Transfection of minigenes carrying mutations associated with DRRD (G118R, R453X, and L467F) into cultured cells detected no missplicing of mRNA from mutant constructs. CONCLUSIONS: Mutations outside the alternatively spliced exon 2 region of COL2A1 can also result in an ocular only phenotype. There was no evidence that missplicing modifies the phenotype of these mutations, suggesting that the minimal or absent systemic features demonstrated by the G118R and L467F mutations are the result of the biophysical changes imparted on the collagen molecule.

Alternative Splicing↗

PubMed2006

A novel mutation of PAX3 in a Chinese family with Waardenburg syndrome.

PURPOSE: The molecular characterization of 34 members of a Chinese family, with 22 members in four generations, affected with Waardenburg syndrome (WS1). METHODS: A detailed family history and clinical data were collected. A genome-wide scan by two-point linkage analysis using more than 400 microsatellite markers in combination with haplotype analysis was performed. Mutation screening was carried out in the candidate gene by sequencing of amplified products. RESULTS: A maximum two-point lod score of 6.53 at theta = 0.00 was obtained with marker D2S2248. Haplotype analysis placed the WS1 locus to a 45.74 cM region between D2S117 and D2S206, in close proximity to the PAX3 gene on chromosome 2q35. Mutation screening in PAX3 identified a 701T > C mutation which converted a highly conserved Leu to Pro. This nucleotide alteration was neither seen in unaffected members of the family nor found in 50 unrelated control subjects. CONCLUSIONS: The present study identified a novel 701T > C mutation in PAX3. The mutation observed in this family highlights the phenotypic heterogeneity of the disorder.

Amino Acid Substitution↗

PubMed2006

Molecular basis of cystic fibrosis in Lithuania: incomplete CFTR mutation detection by PCR-based screening protocols.

Mutational analysis of the cystic fibrosis transmembrane regulator (CFTR) gene was performed in 98 unrelated CF chromosomes from 49 Lithuanian CF patients through a combined approach in which the p.F508del mutation was first screened by allele-specific PCR while CFTR mutations in nonp.F508del chromosomes have been screened for by denaturing gradient gel electrophoresis analysis. A CFTR mutation was characterized in 62.2% of CF chromosomes, two of which (2.0%) have been previously shown to carry a large gene deletion CFTRdele2,3(21 kb). The most frequent Lithuanian CF mutation is p.F508del (52.0%). Seven CFTR mutations, p.N1303K (2.0%), p.R75Q (1.0%), p.G314R (1.0%), p.R553X (4.2%), p.W1282X (1.0%), and g.3944delGT (1.0%), accounted for 10.1% of Lithuanian CF chromosomes. It was not possible to characterize 35.8% of the CF Lithuanian chromosomes. Analysis of intron 8 (TG)mTn and M470V polymorphic loci did not permit the characterization of the CFTR dysfunction underlying the CF phenotype in the patients for which no CFTR mutation was identified. Thus, screening of the eight CFTR mutations identified in this study and of the large deletion CFTRdele2,3(21 kb) allows the implementation of an early molecular or confirmatory CF diagnosis for 65% of Lithuanian CF chromosomes.

Amino Acid Substitution↗

PubMed2005

Identification of a novel splice site mutation of the CSPG2 gene in a Japanese family with Wagner syndrome.

PURPOSE: To investigate the genetic basis and clinical variability of Wagner syndrome, a rare, dominantly inherited vitreoretinopathy. METHODS: Clinical examination, linkage analysis, and mutational screening were performed in a large, three-generation, consanguineous Japanese family with Wagner syndrome. The effect of splice site mutation was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis with lymphoblastoid cell total RNAs generated from affected individuals. RESULTS: Ocular phenotypes of affected members included an empty vitreous with fibrillary condensations, avascular membrane, perivascular sheathing, and progressive chorioretinal dystrophy and were similar to those of the original Wagner syndrome family. All affected eyes examined exhibited pseudoexotropia with ectopic fovea. No systemic manifestations were observed. Genetic linkage confirmed disease segregation with the previously identified WGN1 locus on 5q13-q14. A heterozygous A-->G transversion at the second base of the 3'-acceptor splice site of intron 7 (c.4004-2 A-->G) of the chondroitin sulfate proteoglycan 2 (CSPG2) gene that cosegregated with the disease was identified. Results of RT-PCR analysis indicated that the c.4004-2 A-->G mutation activates a cryptic splice site, located 39 bp downstream from the authentic 3' splice acceptor site. CONCLUSIONS: This linkage study confirmed the genetic homogeneity of the Wagner syndrome. CSPG2 encodes versican, a large chondroitin sulfate proteoglycan, which, in vitreous, binds to hyaluronan and link protein and forms large aggregates that are important for maintaining structural integrity. Although the CSPG2 gene has been excluded as a candidate for causing Wagner syndrome, these data emphasize the necessity of further mutational screening in new families and careful functional characterization.

Adolescent↗

PubMed2006

Spastin gene mutations in Bulgarian patients with hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) is an extremely heterogeneous group of neurodegenerative disorders affecting the longest axons in the central nervous system. The most common genetic form accounting for about 40% of the autosomal-dominant HSP (ADHSP) cases is spastin gene, SPG4. We performed mutation screening of the spastin gene on 36 unrelated HSP patients from three different ethnic groups (Bulgarian, Turks and Gypsies) and found four new mutations and one already reported. The phenotype-genotype correlations in Bulgarian SPG4 patients showed a great difference in the age at disease onset between patients with missense mutations and those harboring deletions and splice-site mutations. Our study is the first to present corroborative clinical data in favor of the general hypothesis that the clinical course of the disease is related to the type of the spastin mutation. The clinical and genealogical findings in Bulgarian SPG4 patients suggest that a positive family history for inheritance as an autosomal-dominant trait is a strong indication for spastin mutation screening.

Adenosine Triphosphatases↗

PubMed1998

A polymorphism in the 5' untranslated region of the human ob gene is associated with low leptin levels.

OBJECTIVE: To search the human ob gene for mutations and evaluate their role in massive obesity. DESIGN: Direct mutation screening of the gene and case-control association study. Multivariate analyses for evaluation of differences in clinical parameters. SUBJECTS: Primary mutation screening: 24 morbidly obese subjects (body mass index (BMI) > 40 kg/m2). Association study: 395 unrelated morbidly obese subjects (BMI > 40 kg/m2), 121 lean, non-diabetic control individuals, 72 women of a random sample with an average BMI 32.5 kg/m2. RESULTS: We report the finding of a DNA variant in exon 1 of the human ob gene (A --> G substitution, base + 19). This variant showed a prevalence of 62% in our study population. Association analyses under different genetic models (dominant, co-dominant, recessive) showed no significant evidence for an association of this variant with BMI. However, obese individuals homozygous for the G-allele showed significantly lower leptin concentrations compared to obese patients either heterozygous or homozygous for the A-allele after correction for BMI. CONCLUSION: Recent linkage studies have shown evidence for linkage of the hsob locus with obesity. Our study provides further evidence that a defect in the ob gene in linkage disequilibrium with the G-allele of exon 1 might be involved in obesity by affecting leptin concentrations.

Adult↗

PubMed2006

A screen for mutations in the transducin gene GNB1 in patients with autosomal dominant retinitis pigmentosa.

PURPOSE: To search for mutations in the GNB1 gene (coding for the transducin beta1-subunit protein) in patients with autosomal dominant retinitis pigmentosa. METHODS: We screened 185 unrelated patients with autosomal dominant retinitis pigmentosa (ADRP) using direct genomic sequencing of the three non-coding exons and 9 coding exons, along with immediately flanking intron DNA. RESULTS: We found 2 polymorphisms, one in intron 1 with a minor allele frequency of 24%, and one in intron 6 with a minor allele frequency of 12% among the 185 patients. Two rare variants (minor allele frequency <1%) were found in the 3' untranslated region of exon 12. No changes were found in the open reading frame (exons 3-11) or in the noncoding exons 1 and 2. CONCLUSIONS: No likely pathogenic GNB1 mutations have been found in any of 185 unrelated patients with ADRP. This result would be expected if hemizygosity for GNB1 does not result in ADRP or is a rare cause of ADRP.

3' Untranslated Regions↗