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At least 217 records · Page 12Linked to original sources

Defining intrahepatic biliary anatomy in living liver transplant donor candidates at mangafodipir trisodium-enhanced MR cholangiography versus conventional T2-weighted MR cholangiography.

PURPOSE: To compare three-dimensional (3D) mangafodipir trisodium-enhanced T1-weighted magnetic resonance (MR) cholangiography with conventional T2-weighted MR cholangiography for depiction and definition of intrahepatic biliary anatomy in liver transplant donor candidates. MATERIALS AND METHODS: One hundred eight healthy liver transplant donor candidates were examined with two MR cholangiographic methods. All candidates gave written informed consent, and the study was approved by the institutional review board. First, breath-hold transverse and coronal half-Fourier single-shot turbo spin-echo and breath-hold oblique coronal heavily T2-weighted turbo spin-echo sequences were performed. Second, mangafodipir trisodium-enhanced breath-hold fat-suppressed 3D gradient-echo sequences were performed through the ducts (oblique coronal plane) and through the entire liver (transverse plane). Interpretation of biliary anatomy findings, particularly variants affecting right liver lobe biliary drainage, and degree of interpretation confidence at both 3D mangafodipir trisodium-enhanced MR cholangiography and T2-weighted MR cholangiography were recorded and compared by using the Wilcoxon signed rank test. Then, consensus interpretations of both MR image sets together were performed. Intraoperative cholangiography was the reference-standard examination for 51 subjects who underwent right lobe hepatectomy. The McNemar test was used to compare the accuracies of the individual MR techniques with that of the consensus interpretation of both image sets together and to compare each technique with intraoperative cholangiography. RESULTS: Biliary anatomy was visualized with mangafodipir trisodium enhancement in all patients. Mangafodipir trisodium-enhanced image findings agreed with findings seen at combined interpretations significantly more often than did T2-weighted image findings (in 107 [99%] vs 88 [82%] of 108 donor candidates, P < .001). Confidence was significantly higher with the mangafodipir trisodium-enhanced images than with the T2-weighted images (mean confidence score, 4.5 vs 3.4; P < .001). In the 51 candidates who underwent intraoperative cholangiography, mangafodipir trisodium-enhanced imaging correctly depicted the biliary anatomy more often than did T2-weighted imaging (in 47 [92%] vs 43 [84%] donor candidates, P = .14), whereas the two MR imaging techniques combined correctly depicted the anatomy in 48 (94%) candidates. CONCLUSION: Mangafodipir trisodium-enhanced 3D MR cholangiography depicts intrahepatic biliary anatomy, especially right duct variants, more accurately than does conventional T2-weighted MR cholangiography.

Adolescent↗

Extreme hypotrophy of the lower body pole, extensive hypoplasia of the spinal column and multiple anomalies of abdominal organs: a maximal variant of the caudal regression sequence?

A newborn with extreme hypotrophy of the lower body pole and aplasia of the lower spinal column is reported. Additional anomalies of internal organs included absence of one kidney and ureter, a diaphragmatic hernia, and anal atresia. Part of the organs located in the lower body pole were necrotic. There were no excretory apertures, and external genitalia were absent. Chromosomal analysis revealed a 46,XY karyotype. The multiple anomalies seen in this newborn may be interpreted as a maximal variant of the caudal regression sequence.

Abnormalities, Multiple↗

Association between CYP2C9 genetic variants and anticoagulation-related outcomes during warfarin therapy.

CONTEXT: Warfarin is a commonly used anticoagulant that requires careful clinical management to balance the risks of overanticoagulation and bleeding with those of underanticoagulation and clotting. The principal enzyme involved in warfarin metabolism is CYP2C9, and 2 relatively common variant forms with reduced activity have been identified, CYP2C9*2 and CYP2C9*3. Patients with these genetic variants have been shown to require lower maintenance doses of warfarin, but a direct association between CYP2C9 genotype and anticoagulation status or bleeding risk has not been established. OBJECTIVE: To determine if CYP2C9*2 and CYP2C9*3 variants are associated with overanticoagulation and bleeding events during warfarin therapy. DESIGN AND SETTING: Retrospective cohort study conducted at 2 anticoagulation clinics based in Seattle, Wash. PARTICIPANTS: Two hundred patients receiving long-term warfarin therapy for various indications during April 3, 1990, to May 31, 2001. Only patients with a complete history of warfarin exposure were included. MAIN OUTCOME MEASURES: Anticoagulation status, measured by time to therapeutic international normalized ratio (INR), rate of above-range INRs, and time to stable warfarin dosing; and time to serious or life-threatening bleeding events. RESULTS: Among 185 patients with analyzable data, 58 (31.4%) had at least 1 variant CYP2C9 allele and 127 (68.6%) had the wild-type (*1/*1) genotype. Mean maintenance dose varied significantly among the 6 genotype groups (*1/*1 [n = 127], *1/*2 [n = 28], *1/*3 [n = 18], *2/*2 [n = 4], *2/*3 [n = 3], *3/*3 [n = 5]) (by Kruskall-Wallis test, chi(2)(5) = 37.348; P<.001). Compared with patients with the wild-type genotype, patients with at least 1 variant allele had an increased risk of above-range INRs (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.03-1.90). The variant group also required more time to achieve stable dosing (HR, 0.65; 95% CI, 0.45-0.94), with a median difference of 95 days (P =.004). In addition, although numbers were small for some genotypes, representing potentially unstable estimates, patients with a variant genotype had a significantly increased risk of a serious or life-threatening bleeding event (HR, 2.39; 95% CI, 1.18-4.86). CONCLUSIONS: The results of our study suggest that the CYP2C9*2 and CYP2C9*3 polymorphisms are associated with an increased risk of overanticoagulation and of bleeding events among patients in a warfarin anticoagulation clinic setting, although small numbers in some cases would suggest the need for caution in interpretation. Screening for CYP2C9 variants may allow clinicians to develop dosing protocols and surveillance techniques to reduce the risk of adverse drug reactions in patients receiving warfarin.

Aged↗

Normal human tissues, in addition to some tumors, express multiple different CD44 isoforms.

At least 20 different isoforms of the human CD44 lymphocyte-homing receptor/hyaluronan receptor have been described to date that arise from the differential splicing of up to 10 alternative exons (termed v1-v10) encoding the membrane-proximal extracellular domain. Although numerous analyses at the mRNA level have indicated tissue-specific expression of CD44 variants, few analyses have been performed at the protein level because of limited availability of suitable monoclonal antibodies. Recently, however, exon-specific monoclonal antibodies have been generated using bacterial fusion proteins, and these have been reported to detect high levels of vCD44 containing the v6 exon on human tumors. Together with earlier evidence linking this particular exon with tumor metastasis in the rat, these latter experiments have led to the interpretation that v6 splice variants play a causative role in tumor dissemination. In this paper we describe the use of a new and comprehensive panel of CD44 exon-specific monoclonal antibodies generated against a recombinant CD44(v3-10)-immunoglobulin chimera to study vCD44 expression in a large number of normal and neoplastic tissues. We show that the expression of vCD44 varies greatly among different human tumors and that some express either very low levels of vCD44 or no CD44 at all. Furthermore, we demonstrate that expression is not limited to isoforms containing the v6 exon but includes variants carrying v3, v4/5, and v8/9. Additionally, normal epithelial tissues are shown to express considerable levels of these same vCD44 isoforms. Such results argue against a ubiquitous role for vCD44 isoforms in promoting tumor growth and metastasis.

Antibodies, Monoclonal↗

Granuloblastomas of the stomach (so-called eosinophilic granulomas)-- a variant of fibrous histiocytomas?

25 cases of focal connective tissue proliferations in the submucosa of the stomach are presented. These lesions are termed "granuloblastomas" and have many features in common with so-called eosinophilic granulomas of the stomach. We found that granuloblastomas may be subdivided into two groups: (1) 8 cases are considered to be the result of the proliferation of a peculiar granulation tissue with abundant eosionophilic granulocytes, and (2) 17 cases show a more or less marked storiform pattern and the cellularity is constituted by fibroblasts and histiocytes as well as differing amounts of eosinophilic granulocytes. After discussing the concept of "fibrous histiocytomas" it is concluded that at least the second group of granuloblastomas may be interpreted as a pseudotumorous variant of fibrous histiocytomas. It remains to be clarified in future if submucosal neurofibromas can show the histological features of lesions which we designate granuloblastomas.

Adult↗

A Case Report of a Pedigree with Distal Hereditary Motor Neuropathy Caused by a Homozygous c.1124G>A Variant an the /*9Vaccinia-Related Kinase 1 Gene.

This study aimed to analyze the clinical phenotypes, neurophysiological characteristics, and pathogenicity of gene variants in a pedigree with distal hereditary motor neuropathy (dHMN) caused by VRK1 variants, and to provide evidence to support clinical diagnosis and genetic counseling for this disease. We report a Chinese consanguineous family with dHMN caused by a homozygous c.1124G>A variant in the VRK1 gene. Clinical and electrophysiological data of the proband were collected. Whole-exome sequencing (WES) and validation by Sanger sequencing were performed to identify the variant site, and pathogenicity interpretation was conducted in accordance with American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines. The proband was a 24-year-old male who presented with 2 years of progressive weakness and atrophy of the distal lower limbs, accompanied by slender upper limbs and no sensory disturbance. Electrophysiological examination showed decreased compound muscle action potential (CMAP) amplitude in motor nerves of both upper and lower limbs, indicating peripheral neurogenic damage, while sensory nerve conduction was normal. Genetic testing detected a homozygous c.1124G>A (p.Trp375Ter) variant in the VRK1 gene. His parents and elder sisters were heterozygous carriers, and the pedigree conformed to autosomal recessive inheritance. According to ACMG guidelines, this variant was classified as pathogenic (evidence: PVS1, PM2, PP1). The homozygous VRK1 c.1124G>A variant causes adult-onset dHMN, rather than pontocerebellar hypoplasia type 1A (PCH1A) as annotated in some genetic databases. This pedigree presents distinctive phenotypes, including slender upper limbs and diffusely decreased CMAP amplitudes in both upper and lower limbs, thereby expanding the clinical and genetic spectrum of VRK1-related dHMN in the Chinese population.

Humans↗

Incidental MSH6 Germline Pathogenic Variant Identified through Tumor-only Comprehensive Genomic Profiling in a Patient with Small Cell Lung Cancer.

A 55-year-old woman was diagnosed with limited-disease small cell lung cancer (LD-SCLC) after incidental detection of a lung nodule. First-line chemotherapy achieved partial response, but recurrence occurred after one year. During second-line therapy, comprehensive genomic profiling (CGP) revealed a germline MSH6 frameshift mutation. Although lung tumor immunohistochemistry showed the retained expression of mismatch repair (MMR) protein, a prior colon cancer specimen showed the loss of MSH6 expression and deficient MMR expression. Germline genetic testing confirmed Lynch syndrome. Cascade testing identified the same mutation in her daughter. This case outlines a tumor-to-germline workflow with testing of at-risk relatives and highlights the importance of prudent interpretation of presumed germline variants.

Humans↗

Report of an angiosarcoma mimic: cutaneous aneurysmal fibrous histiocytoma.

Aneurysmal fibrous histiocytoma is an unusual variant of the spectrum of fibrous histiocytomas with the peculiar morphologic appearance of a benign aneurysmal vasoformative process that ultimately culminates in multiple microhemorrhages within the tumor. It looks strikingly different from the usual cutaneous lesions encountered in clinical dermatology practice. A single report of a cutaneous aneurysmal fibrous histiocytoma in the skin of the back of a 60-year-old male is described with emphasis on the immunostaining pattern and review of the literature. There is a significant potential for confusion of this lesion with other cutaneous lesions, clinically as well as pathologically. In our case, the patient presented with a lesion that clinically resembled a hemangioma, was pathologically interpreted initially to be an angiosarcoma, and finally, the revised pathology was interpreted as an aneurysmal variant of a fibrous histiocytoma. Caution is warranted to avoid misinterpretation of cutaneous fibrohistiocytic tumors.

Aneurysm↗

[Motives for the prescription of antibiotics in the emergency department of the University Hospital Center in Nice. A prospective study].

OBJECTIVES: Since April 1999, we have set-up an infectious disease consultation in the emergency unit of the University Hospital in Nice. Unjustified antiobiotherapy is often initiated. We therefore conducted a survey to study the motives and validity of antibiotic prescriptions. METHOD: This prospective study was conducted in two phases. The first consisted in asking the emergency physicians prescribing antibiotics to fill-in a questionnaire giving information on the diagnosis established and the antiobiotherapy proposed. In the second phase, the diagnoses and corresponding treatments were submitted to 4 experts who assessed the acceptability of the diagnoses and the antibiotics prescribed. The experts only had access to the clinical and para-clinical data available. Moreover, their therapeutic judgement was based on previously published consensuses. RESULTS: The 6-month survey collected 117 questionnaires that could be analysed. The rate of error in diagnosis was of 33% (39/117). Thoracic x-rays could not be interpreted in 11% of cases. In single variant analysis, factors of erroneous diagnosis were due to its interpretation by an internist, the diagnostic category of "broncho-pulmonary infections" and the lack of documentation. In multi variant analysis, only the lack of documentation was related to erroneous diagnosis (OR = 5.5; IC 95% (2.03; 15.30), p < 0.0002). The rate of antibiotherapy not adapted to the diagnosis made by the physician was of 32% (37/117). In 24 cases the modalities of the prescription were incorrect and in 13 cases the prescription was unjustified. Only the status of the prescriber (internist) was statistically associated with an antibiotherapy not adapted to the diagnosis (OR = 2.2; IC 95% (0.93; 5.26), p < 0.05). CONCLUSION: Unjustified antibiotherapy in an emergency unit is generally due to erroneous diagnosis of infection. The lack of documentation and inexperience of the prescribers appear to be the two elements contributing to unjustified antibiotherapy.

Anti-Bacterial Agents↗

Unusual sialilation of three different rare genetic variants of serum DBP: Gc1A17, Gc1A16, and Gc1A11.

The proteins of three anodal Gc1 variants, Gc1A16, 1A11, and 1A17, are characterized by the most acidic isoelectric points observed so far among the different Gc mutants. Stepwise removal of N-acetylneuraminic acid (NANA) by treatment with neuraminidase was performed to estimate the degree of sialilation of these Gc variants. The results indicate that both proteins, the anodal and the cathodal component of these Gc1 mutants, carry sialic acid residues. This observation is remarkable in so far as usually only the anodal component of the Gc1 protein contains NANA and only a single residue. From the experiments carried out it can be deduced that Gc1A16 has two NANA residues in the anodal and one NANA residue in the cathodal component. Gc1A16 was found in four members of three generations in a Danish family; the variant segregated as a Mendelian trait. More difficult to interpret are the results obtained with the variants Gc1A11 and Gc1A17. Gc1A11 probably has three NANA residues in the anodal and two NANA residues in the cathodal component. Gc1A11 has been observed in two mother-child pairs and is presumably also a simple genetic trait. Gc1A17 has also several NANA residues in both Gc proteins; it is suggested that the anodal component has either three or four NANA residues and the cathodal component either two or three NANA residues. Family information on this variant is not yet available.

Alleles↗

The normal suprasellar subarachnoid space in computed tomography.

Changes in visibility or configuration of the suprasellar cistern are often the only signs on a CT scan of a patient with a juxtasellar expansion. Normal variations of this subarachnoid space on a CT scan are side for anatomical and technical reasons. The ability to differentiate between normal and abnormal in this area is essential in interpreting computed axial tomograms. To determine normal variants of the suprasellar cistern, 456 consecutive standard tomograms interpreted as normal were reviewed. The cistern was visible in 73.7% of the scans and the shape of the cistern was found to be either hexagonal (71.5%) or tetragonal (28.5%). The visible content of the cistern included the anterior part of the third ventricle (55.5%), the optic nerves and/or chiasm (52%) and the dorsum sellae (34.9%). The content of the cistern could not be accurately defined in 24.8% of the scans. In about one-fourth of the scans the suprasellar subarachnoid space was not visualised at all. If any doubt exists as to the visibility and configuration of the suprasellar cistern when there is a clinical suspicion of a juxtasellar tumour, additional investigations must be performed.

Brain↗

Role of MC1R variants in uveal melanoma.

Variants of the melanocortin-1 receptor (MC1R) gene have been linked to sun-sensitive skin types and hair colour, and may independently play a role in susceptibility to cutaneous melanoma. To assess the role of MC1R variants in uveal melanoma, we have analysed a cohort of 350 patients for the changes within the major region of the gene displaying sequence variation. Eight variants were detected - V60L, D84E, V92M, R151C, I155T, R160W, R163Q and D294H - 63% of these patients being hetero- or homozygous for at least one variant. Standard melanoma risk factor data were available on 119 of the patients. MC1R variants were significantly associated with hair colour (P=0.03) but not skin or eye colour. The frequency of the variants detected in the 350 patients was comparable with those in the general population, and comparison of the cumulative tumour distribution by age at diagnosis in carriers and noncarriers provided no evidence that MC1R variants confer an increased risk of uveal melanoma. We interpret the data as indicating that MC1R variants do not appear to be major determinants of susceptibility to uveal melanoma.

Adult↗

Effect of serinate ligation at each of the iron sites of the [Fe4S4] cluster of Pyrococcus furiosus ferredoxin on the redox, spectroscopic, and biological properties.

Pyrococcus furiosus ferredoxin (Fd) contains a single [Fe(4)S(4)] cluster coordinated by three cysteine (at positions 11, 17, and 56) and one aspartate ligand (at position 14). In this study, the spectroscopic, redox, and functional consequences of D14C, D14C/C11S, D14S, D14C/C17S, and D14C/C56S mutations have been investigated. The four serine variants each contain a potential cluster coordination sphere of one serine and three cysteine residues, with serine ligation at each of the four Fe sites of the [Fe(4)S(4)] cluster. All five variants were expressed in Escherichia coli, and each contained a [Fe(4)S(4)](2+,+) cluster as shown by UV-visible absorption and resonance Raman studies of the oxidized protein and EPR and variable-temperature magnetic circular dichroism (VTMCD) studies of the as-prepared, dithionite-reduced protein. Changes in both the absorption and resonance Raman spectra are consistent with changing from complete cysteinyl cluster ligation in the D14C variant to three cysteines and one oxygenic ligand in each of the four serine variants. EPR and VTMCD studies show distinctive ground and excited state properties for the paramagnetic [Fe(4)S(4)](+) centers in each of these variant proteins, with the D14C and D14C/C11S variants having homogeneous S = (1)/(2) ground states and the D14S, D14C/C17S, and D14C/C56S variants having mixed-spin, S = (1)/(2) and (3)/(2) ground states. The midpoint potentials (pH 7.0, 23 degrees C) of the D14C/C11S and D14C/C17S variants were unchanged compared to that of the D14C variant (E(m) = -427 mV) within experimental error, but the potentials of D14C/C56S and D14S variants were more negative by 49 and 78 mV, respectively. Since the VTMCD spectra indicate the presence of a valence-delocalized Fe(2. 5+)Fe(2.5+) pair in all five variants, the midpoint potentials are interpreted in terms of Cys11 and Cys17 ligating the nonreducible valence-delocalized pair in D14C. Only the D14S variant exhibited a pH-dependent redox potential over the range of 3.5-10, and this is attributed to protonation of the serinate ligand to the reduced cluster (pK(a) = 4.75). All five variants had similar K(m) and V(m) values in a coupled assay in which Fd was reduced by pyruvate ferredoxin oxidoreductase (POR) and oxidized by ferredoxin NADP oxidoreductase (FNOR), both purified from P. furiosus. Hence, the mode of ligation at each Fe atom in the [Fe(4)S(4)] cluster appears to have little effect on the interaction and the electron transfer between Fd and FNOR.

Amino Acid Sequence↗

Pathology of transitional cell carcinoma of the bladder and its clinical implications.

Transitional cell carcinomas are divided into superficial and muscle-invasive tumors. Most of them are superficial tumors, and approximately 15-20% are muscle-invasive carcinomas. Pathologists play a significant role in diagnosing bladder tumors and in reporting features important for determining prognosis. We will review the cytologic and histopathologic features that help determine prognosis, including depth of invasion, tumor grade, multicentricity, tumor size, and the presence of vascular/lymphatic invasion, blood group antigen expression, proliferative indices, and molecular markers. Brief mention will be made of specimen handling, interpretation, reporting, and histologic variants of transitional cell carcinoma.

ABO Blood-Group System↗

Automated mass correction and data interpretation for protein open-access liquid chromatography-mass spectrometry.

Characterization of recombinant protein purification fractions and final products by liquid chromatography-mass spectrometry (LC/MS) are requested more frequently each year. A protein open-access (OA) LC/MS system was developed in our laboratory to meet this demand. This paper compares the system that we originally implemented in our facilities in 2003 to the one now in use, and discusses, in more detail, recent enhancements that have improved its robustness, reliability, and data reporting capabilities. The system utilizes instruments equipped with reversed-phase chromatography and an orthogonal accelerated time-of-flight mass spectrometer fitted with an electrospray source. Sample analysis requests are accomplished using a simple form on a web-enabled laboratory information management system (LIMS). This distributed form is accessible from any intranet-connected company desktop computer. Automated data acquisition and processing are performed using a combination of in-house (OA-Self Service, OA-Monitor, and OA-Analysis Engine) and vendor-supplied programs (AutoLynx, and OpenLynx) located on acquisition computers and off-line processing workstations. Analysis results are then reported via the same web-based LIMS. Also presented are solutions to problems not addressed on commercially available, small-molecule OA-LC/MS systems. These include automated transforming of mass-to-charge (m/z) spectra to mass spectra and automated data interpretation that considers minor variants to the protein sequence-such as common post-translational modifications (PTMs). Currently, our protein OA-LC/MS platform runs on five LC/MS instruments located in three separate GlaxoSmithKline R&D sites in the US and UK. To date, more than 8000 protein OA-LC/MS samples have been analyzed. With these user friendly and highly automated OA systems in place, mass spectrometry plays a key role in assessing the quality of recombinant proteins, either produced at our facilities or bought from external sources, without dedicating extensive amounts of analyst resource.

Animals↗

Zonal colonic aganglionosis.

The customary approach to the diagnosis of Hirschsprung's disease is based on the existence of a single distal aganglionic region extending to the anal margin. Segmental aganglionosis, however, may involve only a limited segment of colon which is interposed between lengths of normal bowel. Awareness of this variant aids in the interpretation of the barium enema in children with signs and symptoms of aganglionosis, especially when the rectal biopsy is normal.

Colon, Sigmoid↗

Correction of the anomalous electrophoretic behavior of ribonuclease A.

Ribonuclease A behaves anomalously on polyacrylamide gel electrophoresis at acid pH. The distance traveled by the protein is a function of the amount of enzyme added at the lower range of detectable activity (10 pg to 100 ng). Addition of myoglobin (1 mg/ml) abolishes the anomaly. The observations are consistent with the known affinity of RNase for anions. Caution is warranted in the interpretation of apparent electrophoretic variants of RNase observed at low concentrations of enzyme.

Animals↗

[Immunogenetics--HLA-association, molecular chaperones and "related" diseases].

The association of rheumatoid arthritis (RA) with the HLA complex has been well established since 1978. But what does that mean? After reminding the reader of some existing immunological interpretations, a more recent variant is introduced. Antigens and molecular chaperones of the HSP70 family form complexes, which interact with HLA-DR beta-chains, especially of the DRB1*0401 genotype, which is the most common among patients with RA in our region. This mechanism might bring *0401(+) persons an advantage in defence against microorganisms, but a disadvantage concerning autoimmunity. Chaperone machines are upregulated in synovial tissue of RA patients. As their number and variety is huge in humans, there exist many possibilities for function, reaching from antigen presentation to immune regulation. In addition to the HLA complex, the "genetic background" plays an important role for the development of an autoimmune disease. This is demonstrated in families of patients with RA or scleroderma, where a high percentage of first degree relatives suffer from a "related" disease.

Animals↗