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The pathogenic classification of glaucomas.

On the basis of a pathogenic definition, our classification distinguished for each of the first intersections a main--mostly determinant mechanism and a secondary mechanism, mostly modulating the damages: hydrodynamic alteration and tissue resistance alteration--for the second intersection, outflow block and hypersecretion--for the third. Reflecting the state of present knowledge, from the corresponding forms of the disease, only outflow block glaucoma is completely analysed, the exogenous, trabecular, pretrabecular and mixed glaucomas being described. In order to permit the correct framing of all pretrabecular block glaucomas, the posterior push forms (retrovitreal or parietal) were introduced besides the anterior already described forms (pupillary or angular). As for low tissue resistance glaucomas, genetic, cardiovascular, metabolic, haematologic and ocular influences are mentioned. This classification avoids the theoretical inadvertencies of previous classifications offering the synthetic frame of a coherent system, open to any new developments, all inclusive, terminologically clear and with direct therapeutic references.

Glaucoma

[Multidimensional analysis in clinical investigation. Application to the pathogenic classification of idiopathic hypercalciuria].

Multidimensional analytical techniques enable any number of variables to be studied simultaneously. These techniques have been described and a few examples of their application to biomedical research given. A classification of so called "idiopathic hypercalciuria" was made using this approach which demonstrated the existence of three possible mechanisms of pathogenesis.

Analysis of Variance

Genetic variability for pathogenicity, isozyme, ribosomal DNA and colony color variants in populations of Rhynchosporium secalis.

Samples of Rhynchosporium secalis were collected from two experimental barley populations known to carry a diverse array of alleles for resistance to this fungal pathogen. Classification of 163 isolates for four putative isozyme systems, a colony color dimorphism and 20 ribosomal DNA restriction fragment length variants revealed 49 different multilocus phenotypes (haplotypes). The six most common haplotypes differed significantly in pathogenicity. Genetic analyses of the data indicated that effective population sizes of the fungus were very large, that the effects of genetic drift were small, and that negligible recombination occurred in the populations studied. Frequency dependent selection was suggested as an explanation for the maintenance of variation in pathogenicity in the fungus.

DNA, Fungal

H4C5 missense variant leads to a neurodevelopmental phenotype overlapping with Angelman syndrome.

Recurrent de novo missense variants in H4 histone genes have recently been associated with a novel neurodevelopmental syndrome that is characterized by intellectual disability and developmental delay as well as more variable findings that include short stature, microcephaly, and facial dysmorphisms. A 4-year-old male with autism, developmental delay, microcephaly, and a happy demeanor underwent evaluation through the Undiagnosed Disease Network. He was clinically suspected to have Angelman syndrome; however, molecular testing was negative. Genome sequencing identified the H4 histone gene variant H4C5 NM_003545.4: c.295T>C, p.Tyr99His, which parental testing confirmed to be de novo. The variant met criteria for a likely pathogenic classification and is one of the seven known disease-causing missense variants in H4C5. A comparison of our proband's findings to the initial description of the H4-associated neurodevelopmental syndrome demonstrates that his phenotype closely matches the spectrum of those reported among the 29 affected individuals. As such, this report corroborates the delineation of neurodevelopmental syndrome caused by de novo missense H4 gene variants. Moreover, it suggests that cases of clinically suspected Angelman syndrome without molecular confirmation should undergo exome or genome sequencing, as novel neurodevelopmental syndromes with phenotypes overlapping with Angelman continue to be discovered.

Male

Dual Aberrant Splicing Caused by an Apparently Missense CHD7 Variant, c.5273A>G (p.Asp1758Gly), in CHARGE Syndrome.

CHARGE syndrome is a rare congenital disorder primarily attributed to heterozygous pathogenic variants of the CHD7 gene. Most pathogenic CHD7 variants are loss-of-function (LoF) variants, whereas the interpretation of missense variants remains challenging in the absence of functional evidence for their pathogenicity. We report a female infant presenting with clinical features characteristic of CHARGE syndrome. Targeted sequencing identified a heterozygous CHD7 variant (NM_017780.4:c.5273A>G), initially annotated as a missense substitution p.Asp1758Gly. This variant has been previously reported and registered with conflicting pathogenicity classifications; however, its transcript-level consequences remain unclear. Long-PCR-based RNA sequencing of total RNA from peripheral blood mononuclear cells revealed two aberrant splicing patterns associated with the variant: a predominant transcript carrying a 28-bp deletion due to cryptic donor splice-site activation, and a minor transcript with partial intron 24 retention. Both transcripts were predicted to result in premature termination codons. These findings demonstrate that c.5273A>G functions as a LoF variant through dual aberrant splicing rather than a simple missense substitution. This case underscores the importance of RNA-level splicing analysis for the accurate interpretation and classification of CHD7 missense variants.

CHD7

Vaginal intraepithelial neoplasia. Report of 14 cases.

From 1978 to 1985 we have found 14 cases of vaginal intraepithelial neoplasia (VAIN) in patients previously hysterectomized. VAIN was detected by an abnormal cytology; diagnostic process included a second cytology, colposcopy, Schiller test, and directed biopsies. VAIN was classified as grade I in 5 patients (35.7%); grade II in 5 patients (35.7%); and grade III in 4 patients (28.6%). Pathogenic classification of VAIN was: VAIN de novo 9 cases (64.3%); VAIN after vaginal irradiation, 3 cases (21.4%); VAIN following incomplete removal of a cervical intraepithelial neoplasia, one case (7.1%); and VAIN as manifestation of a multicentric neoplasia of the lower genital tract, one case (7.1%). The mean time between hysterectomy and VAIN diagnosis was 6.9 years; this time was larger for those women hysterectomized by benign uterine diseases (9.0 years vs. 2.4 years). Our conclusion is that patients who have lost their uterus by malignant or benign diseases should be followed-up with periodic vaginal cytology in order to detect vaginal neoplasia in its pre-invasive stages.

Adult

Estimation of carrier frequencies of autosomal and X-linked recessive genetic conditions based on gnomAD v4.0 data in different ancestries.

PURPOSE: Monogenic rare diseases contribute significantly to infant deaths and pediatric hospitalizations and cause burden to the patients and their families. The American College of Medical Genetics and Genomics recommended in 2021 that carrier screening of autosomal recessive and X-linked conditions with a carrier frequency of ≥1/200 and a severe or moderate phenotype should be offered when planning or during pregnancy. In November 2023 gnomAD v4.0 was released. It contains in total 807,162 individuals, being nearly 5× larger than previous versions, which have been used to estimate gene carrier frequencies (GCF). METHODS: We utilized gnomAD v4.0 (GRCh38) to calculate the GCFs for available genetic ancestry groups for variants having pathogenic or likely pathogenic classification (>80% of submissions) in ClinVar. We calculated GCF separately for exomes and genomes, combined data, and at-risk couple frequencies (ACF) per genetic ancestry group. RESULTS: In total, 324 genes had a GCF ≥1/200 in at least 1 ancestry subgroup. The number of genes with GCF ≥1/200 varied greatly between subgroups. ACFs were more similar, Ashkenazi Jewish having the highest ACF of 6.11%. CONCLUSION: Improved understanding of carrier risks and updated carrier screening content would allow patients to make more informed reproductive decisions.

Humans

Proliferation and hyperplasia of vascular endothelium in human skin.

In a number of diseases of the skin, proliferation of endothelial cells is altered. Replication of endothelial cells has been evaluated by incorporating tritiated thymidine, and compared in inflammatory and neoplastic disorders. An attempt at pathogenic classification is proposed.

Biopsy

Unraveling a novel FBN1 variant in Marfan syndrome with dilated aortic root manifestation.

BACKGROUND: Marfan syndrome (MFS) is a genetic disorder affecting connective tissue, with variable incidence rates. A significant portion of cases stems from novel genetic variants, while others inherit it from affected parents. OBJECTIVE: This study focuses on identifying the genetic cause of MFS in a specific family, using whole-exome sequencing (WES). METHODS: A 15-year-old male with confirmed MFS was examined, showing symptoms of palpitations and severe mitral valve regurgitation. WES was performed, followed by confirmation with Sanger sequencing. Variants were assessed for pathogenicity using bioinformatics tools and the American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS: One potentially novel pathogenic variant was found in exon 14 of the FBN1 gene: c.1676delCinsAAT, p.Ala559GlufsTer21. In silico analysis suggested a deleterious impact on protein structure and function, supporting their pathogenic classification. CONCLUSION: The identification of this novel variant highlights the importance of the FBN1 gene in MFS, especially its cardiovascular manifestations. Early intervention can improve patient outcomes, while ongoing research holds promise for further advancements in treatment for Marfan syndrome.

Humans

Exploring the Melanoma and Pancreatic Cancer Phenotype of a Potential CDKN2A Founder Variant, I49T (c.146T>C; p.Ile49Thr), in Individuals of Predominantly Mexican Ancestry.

PURPOSE: Pathogenic/likely pathogenic variants (P/LPVs) in the CDKN2A gene cause an increased risk of melanoma (MEL) and pancreatic cancer (PANC). The CDKN2A variant I49T (c.146T>C), reported to be recurrent in Hispanics, has conflicting pathogenicity classifications at laboratories, affecting clinical care. Multiple genetics clinics collaborated to explore cancers associated with I49T. METHODS: Institutional clinical databases were queried for the CDKN2A variants, I49T, known P/LPVs, and c.-2G>A (a benign variant [BV]), and history of PANC and MEL was abstracted. A combination of statistical tests was used to investigate cancer history associations. RESULTS: Data on 203 individuals, with qualifying CDKN2A variants detected on multigene testing between 2012 and 2023, were analyzed (I49T, n = 101; known CDKN2A P/LPVs, n = 57; BV, n = 45). Those with I49T were 91% less likely to have MEL than known CDKN2A P/LPVs (odd ratio [OR] = 0.089 [95% CI, 0.031 to 0.025]; P < .001) and were also less likely to have PANC (OR = 0.45 [95% CI, 0.14 to 1.41]; P = .17). However, mean age at PANC diagnosis for I49T was 56.0 years, significantly younger than known CDKN2A P/LPVs (&#x3bc; = 71.0 years; P = .026). CONCLUSION: In the largest I49T study to date to our knowledge, MEL was significantly less frequent compared with known CDKN2A P/LPVs. Although a nonsignificant trend was observed for less PANC in I49T than known P/LPVs, individuals with I49T presented with PANC at a significantly younger age than those with known CDKN2A P/LPVs. The presence of I49T in Hispanics of mostly Mexican ancestry supports that it is a founder variant, relevant to understanding cancer risk in a large proportion of Hispanics in the United States.

Humans

[An anatomicoclinical analysis of the synovial plica syndrome].

The authors describe embryology and anatomy of synovial plica of the knee joint. They propose a clinic and pathogenic classification and after examining the diagnostic problem of plica syndrome, analyze their long-term results after surgical treatment.

Humans

[Perforations of the dura mater during epidural anesthesia. The value of epidurography].

The authors propose a pathogenic classification of perforations of the dura mater occurring during continuous epidural anaesthesia: according to the flow through the communication with the subarochnoid space. Two clinical forms of anaesthesia affecting the cord itself may be distinguished on this basis, one frequent and of immediate onset, diagnosed by the "test dose" and the other rare, of delayed onset, where this safety measure does not suffice. Routine prior epidurography is suggested, in order to ensure the diagnosis of dura mater perforation. In the case of the latter, it show either a more or less typical appearance of radicolography only or, more rarely, a picture which combines opacification of the epidural space with the subarachnoid passage of the contrast medium. This "mixed" appearance, although rare, should be known since it makes it possible to prevent delayed total spinal anaesthesia.

Aged

[Evaluation of the lysozyme and DNAase activity for the identification of pathogenic staphylococci].

The sensitivity of two tests recently proposed for the classification of pathogen staphylococci were evaluated: --production of DNA-ase with the modified method of Lachica et al.; --production of lisozyme. The two above tests were studied with other six tests on 1,000 strains of staphylococci showing a very high specificity. The Authors propose that the DNA-ase production and the lisozyme production, also for their very simple execution, should become routine tests to identify the strains of pathogenic staphylococci.

Deoxyribonucleases

Primary amoebic meningoencephalitis.

As a serendipitous by-product of polio virus research, a highly fatal amoebic meningoencephalitis was recognized in animals. The causative microorganisms, contaminants of the viral cultures, were identified as small soil amoebae. These organisms, previously considered non-pathogenic, are prevalent throughout the world. Based on animal studies, the original investigators suggested the possibility of a similar disease in humans. Seven years later, human cases of amoebic meningoencephalitis were reported from widely separated areas of the world. Since 1965, a total of 79 cases have been reported. The literature of primary amoebic meningoencephalitis is presented. The history of the discovery and elucidation of this disease is reviewed. The 79 cases reported in the world literature are divided into two groups, those diagnosed retrospectively after reviewing previous deaths from meningoencephalitis, and those diagnosed at the time of the illness. The classification, morphology, pathogenicity, virulence and distribution of pathogenic soil amoebae are reviewed. The presenting clinical findings, diagnostic procedures, pathology, and management of this recently recognized, highly fatal, human disease is presented along with a report of a new case. Otolaryngologists should become familiar with this serious disorder with a transnasal portal of entry.

Amebiasis

Large-scale functional annotation establishes a reference framework for human LRRK2 variants.

Pathogenic variants in leucine-rich repeat kinase 2 (LRRK2)1are among the most frequent monogenic causes of Parkinson's disease (PD)2 and act through a gain-of-function mechanism of increased kinase activity. LRRK2-targeted therapies are in clinical development, but interpretation of the rapidly expanding catalogue of rare LRRK2 variants remains a barrier to translation. Here, we present functionally annotated data on >350 LRRK2 coding variants using a standardized cellular assay with Rab10 phosphorylation as a readout of kinase activity and integrated these data with curated genetic and clinical annotations from the Movement Disorders Society Genetic Mutation Database (MDSGene). Variants differed in activation magnitude, ranging from modest increases (e.g., p.G2019S) to strongly activating substitutions such as p.Y1699C or p.L1795F. Activating variants occurred across the full length of LRRK2, although the largest effects clustered within the ROC-COR regulatory hub, where structural analysis identified subdomains forming an allosteric scaffold controlling kinase output. All known/established pathogenic variants showed increased activity, whereas benign and likely benign variants remained within the wild-type range. Functional effect sizes correlated with pathway activation in patient-derived immune cells, altogether providing a framework for ACMG-based variant interpretation in which kinase activation can support PS3 functional evidence for reclassification of variants.

Protein phosphorylation