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Results for “Variant classification”

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At least 145 records · Page 8Linked to original sources
PubMed1990

[Classification of the types of blood supply of the muscles from the standpoint of plastic surgery].

Based on an experience with 120 composite flaps including the muscle and with special account of literature data the author describes a new classification of types of blood supply of muscles. The author proposes 6 types of blood supply of muscles and substantiates a direct relationship between the anatomy of muscle vessels and variants of its use for plasty. A comparison of the new classification and other classifications was made.

Blood Vessels↗
PubMed1991

[Effects of immunologic markers on prognosis in acute lymphoblastic leukemia in young children].

Altogether 77 children aged up to 3 years with acute lymphoblastic leukemia (ALL) were examined for the immunological phenotype of blast cells. L1, L1/L2, L2/L1, L2 variants of ALL and the undifferentiated one were established in accordance with criteria of the FAB classification. T1, zero and Ia immunosubvariants were recorded most frequently. Mature cell T2 and pre-B variants (3 and 2 cases, respectively) were rare; B-cellular acute lymphoblastic leukemia was lacking; the "common" subvariant was revealed in 28 patients. The patients' age produced the highest effect on the prognosis: the significantly least disease standing and remissions were noted in a group of children under 2 years as compared to those aged 2 to 3 years. As for immunological markers, expression of Thy1-antigen exerted an unfavourable effect on the prognosis and duration of the first remission.

Antibodies, Monoclonal↗
PubMed1976

Classification and survival rate of patients with serous cystadenocarcinoma of the ovaries.

The comparative evaluation of two stage classifications including USSR Ministry of Health stage classification and TNM system was performed on the base of studies of the end results of 419 patients with serous cystadenocarcinoma of the ovaries. It has been established that TNM system is of a greater importance in establishing more accurate prognosis than the stage classification of the Ministry of Health. In TNM system four variants of the degree of extension correspond to each stage that allows to evaluate not only the extent of the primary tumor that also of the metastatic spread. The achieved results point to the superiority of the TNM system and serve as a base for transition to the TNM system in the classification of ovarian carcinoma.

Cystadenocarcinoma↗
PubMedDate not supplied

Hürthle cell (oxyphilic) papillary thyroid carcinoma: a variant with more aggressive biologic behavior.

The latest World Health Organization International Classification defines papillary thyroid carcinoma by its "follicular cell differentiation...as well as characteristic nuclear changes". However the oxyphilic (Hürthle cell) papillary carcinoma have nuclei which generally resemble the nuclei seen in oxyphilic follicular carcinomas, and such oxyphilic papillary tumors may behave more aggressively than typical papillary cancers. To further characterize these rare tumors, we identified during a 32-year period 22 patients with oxyphilic papillary cancer and compared them with 1,084 patients with typical papillary cancers and 57 patients with oxyphilic follicular cancers treated by the Mayo surgical group during the same time period. Although typical papillary and oxyphilic papillary cancers were comparable with regards to patient age, tumor size and extent, TNM stage, and prognostic score (AGES), there were significant differences. Compared to typical papillary tumors, oxyphilic papillary cancers had fewer neck nodal metastases at primary diagnosis (5% vs 40%, p less than 0.0001), were more often DNA non-diploid (71% vs 21%, p less than 0.001), and after 10 postoperative years had higher rates of both tumor recurrence (28% vs 11%, p less than 0.0001) and cause-specific mortality (1.7% vs 4%, p less than 0.0005). In these four important respects the oxyphilic papillary cancers more resembled the oxyphilic follicular cancers. For oxyphilic follicular cancers, the frequency of initial neck nodal metastases was 7% (cf 5%); 83% of the oxyphilic follicular tumors were non-diploid (cf 71%), and at 10 years postoperatively the tumor recurrence and cause-specific mortality rates were 28% and 18%, insignificantly different from 28% and 17% seen with the oxyphilic papillary cancers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2025

Uveal Melanoma and the Lynch Syndrome Tumor Spectrum.

IMPORTANCE: To date, no environmental factors and few therapeutic options are known for uveal melanoma (UM), the most common malignant intraocular primary tumor in adults. Identification of new predisposition factors could lead to better monitoring and possibly improved treatments of patients with UM. OBJECTIVE: To identify new genetic alterations predisposing for UM. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study conducted at Institut Curie in Paris, France, among 381 consecutive patients diagnosed with UM between July 2021 and February 2023. UM was diagnosed clinically by ophthalmologists, and a senior pathologist confirmed the diagnosis when tumor or biopsy was available. All participants received genetic counseling and consented to extended genetic testing. A panel of 122 genes predisposing to cancer were analyzed by targeted sequencing on germline DNA from these patients. MAIN OUTCOMES AND MEASURES: Frequency of pathogenic variants (PVs) in genes from a targeted panel, with classification of germline PVs done according to the American College of Medical Genetics and Genomics guidelines and the French Unicancer Genetics Group. RESULTS: A total of 79 PVs were identified in 70 participants (41 female and 29 male; mean [SD] age, 60.6 [15.3] years). Among them, 21 were found in clinically relevant genes, with an enrichment in the mismatch repair (MMR) genes, involved in Lynch syndrome, a frequent predisposition to colon and endometrial cancers. This finding suggested MMR germline PVs could also predispose to UM. One tumor was available from a participant carrying a MLH1 germline PV. The tumor exhibited a monosomy 3 with loss of the wild-type allele of MLH1, located on chromosome 3. Loss of expression of MLH1 was observed by immunohistochemistry, and MMR variant signatures SBS6, ID1, and ID2 were identified from the whole-genome sequencing of this tumor, supporting the possibility that MLH1 contributes to the oncogenesis of this UM. CONCLUSIONS AND RELEVANCE: This prospective germline study on patients with UM provided evidence supporting the notion that MMR germline alterations are enriched among patients with UM and may contribute to oncogenesis of UM, and that UM may therefore be a rare tumor manifestation of Lynch syndrome.

Humans↗
PubMed1988

Multilobated non-Hodgkin's lymphoma. A clinicopathologic entity.

Multilobated non-Hodgkin's lymphomas (NHL) have recently been recognized as an NHL variant. During a period of 10 years we observed 30 individuals with NHL in which more than 30% of the malignant cells had a characteristic multilobation. The immunologic phenotype was determined in 14 of these cases. One was of T-cell lineage, and the others exhibited B-lymphoid markers. Sixty-eight percent of the patients presented with extranodal localizations. In the clinical follow-up a complete remission was observed in 78% of patients with a mean duration of 37 months (range, 5 to 120 months). The actuarial survival after 5 years was 45%. From these data we conclude that multilobated NHL are comparable to diffuse, large cleaved-cell NHL of an intermediate grade malignancy according to the Working Formulation or are comparable to the diffuse centrocytic-centroblastic NHL according to the Kiel classification. The neoplastic cells are to be considered as variants of follicle center cells, but the clinicopathologic correlation indicates that multilobated NHL represent a distinct nosologic entity.

Adolescent↗
PubMed2026

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↗
PubMed1990

A new von Willebrand factor (vWF) defect in a patient with factor VIII (FVIII) deficiency but with normal levels and multimeric patterns of both plasma and platelet vWF. Characterization of abnormal vWF/FVIII interaction.

The patients with inherited bleeding diathesis related to quantitative, structural, and/or functional abnormalities of von Willebrand factor (vWF) are said to have von Willebrand's disease (vWD). We report here the clinical and laboratory features of a 50-year-old woman with a life-long history of excessive bleeding. Her particular laboratory data are factor VIII (FVIII) deficiency, subnormal bleeding time, and the presence of all plasma and platelet vWF multimers in normal amounts. Infused with FVIII/vWF concentrate, she showed a persistent increase in FVIII that led us to discard hemophilia A carrier or "acquired hemophilia" diagnoses. vWF devoid of FVIII purified from normal and patient's plasma by immunoaffinity on anti-vWF monoclonal antibody (MoAb) was immobilized onto polystyrene tubes that were further incubated with purified normal FVIII. The bound FVIII was evidenced using radiolabeled anti-FVIII MoAb. The data showed that the patient's vWF, in contrast to vWF purified from normal plasma, was unable to bind FVIII. Furthermore, no inhibitor of FVIII/vWF interaction was evidenced in incubating purified normal vWF with the patient's plasma before the addition of FVIII and anti-FVIII MoAb. These results support the concept that the bleeding diathesis of this patient appears to be due mainly to her abnormal vWF preventing FVIII/vWF interaction. This abnormality, which is not yet described in present classification of vWD, could be considered as a new variant of vWD.

Factor VIII↗
PubMedDate not supplied

Von Willebrand factor and von Willebrand's disease: a complex protein and a complex disease.

Von Willebrand factor is a complex protein which is important in several ways for normal hemostasis. Von Willebrand's disease results when there is either a quantitative or qualitative disorder of von Willebrand factor. In this review, the structure and function of von Willebrand factor are discussed. Additionally, the current laboratory and clinical classification of von Willebrand's disease and closely related variants are outlined.

Factor VIII↗
PubMed2025

CAKL: Commutative algebra k-mer learning of genomics.

Despite the availability of various sequence analysis models, comparative genomic analysis remains a challenge in genomics, genetics, and phylogenetics. Commutative algebra, a fundamental tool in algebraic geometry and number theory, has rarely been used in data and biological sciences. In this study, we introduce commutative algebra k-mer learning (CAKL) as the first-ever nonlinear algebraic framework for analyzing genomic sequences. CAKL bridges between commutative algebra, algebraic topology, combinatorics, and machine learning to establish a new mathematical paradigm for comparative genomic analysis. We evaluate its effectiveness on three tasks-genetic variant identification, phylogenetic tree analysis, and viral genome classification-typically requiring alignment-based, alignment-free, and machine-learning approaches, respectively. Across eleven datasets, CAKL outperforms five state-of-the-art sequence analysis methods, particularly in viral classification, and maintains stable predictive accuracy as dataset size increases, underscoring its scalability and robustness. This work ushers in a new era in commutative algebraic data analysis and learning.

Journal Article↗
PubMed1976

[Epithelial tumors of the liver (histology, histogenesis, classification)].

Under study were 120 epithelial hepatic tumors. The problems of histology, histogenesis, classification, morphogenesis of hepatic tumors are being under consideration from the point of view of modern oncology with due account of tumor progression and its development in tumor field. Various trends of differentiation with isolation of histologic variants of epithelial tumors of the liver have been shown. The histological classification is suggested.

Adenocarcinoma↗
PubMed1986

Immunohistochemical study of small cell lung carcinoma; with special reference to the neuroendocrine markers aromatic L-amino acid decarboxylase and gastrin-releasing peptide.

Forty-seven surgically resected small cell lung carcinomas (SCLC) were immunohistochemically studied by using antibodies to various neuroendocrine and epithelial markers. SCLC was shown to be subdivided into two categories, with and without the immunoreactive neuroendocrine markers aromatic L-amino acid decarboxylase, gastrin-releasing peptide, serotonin, chromogranin A and neurofilament protein. Neuron-specific enolase (NSE) and creatine kinase BB isoenzyme (CK-BB), which are also considered to be neuroendocrine markers, had a tendency to be widely distributed in the SCLC with a neuroendocrine marker, but the immunoreactivity for both NSE and CK-BB varied in the SCLC without neuroendocrine markers. Therefore they were not included in the classification. Epithelial markers keratin, involucrin and epithelial membrane antigen were frequently observed in the SCLC with neuroendocrine markers, but less so in the SCLC without neuroendocrine markers. The data are discussed briefly in relation to "classic and variant" forms of SCLC in vitro and to a recently proposed histological classification of SCLC.

Aromatic-L-Amino-Acid Decarboxylases↗
PubMed1991

Structural and antigenic polymorphism of the 35- to 48-kilodalton merozoite surface antigen (MSA-2) of the malaria parasite Plasmodium falciparum.

Merozoite surface antigen MSA-2 of the human parasite Plasmodium falciparum is being considered for the development of a malaria vaccine. The antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of MSA-2 among 25 parasite isolates. The variants are grouped into two major serogroups, A and B. Genes encoding two different variants from serogroup A have been sequenced, and their DNA together with deduced amino acid sequences were compared with sequences encoded by other alleles. The comparison shows that the serological classification reflects differences in DNA sequences and deduced primary structure of MSA-2 variants and serogroups. Thus, the overall homologies of DNA and amino acid sequences are over 95% among variants in the same serogroup. In contrast, similarities between the group A variants and a group B variant are only 70 and 64% for DNA and amino acid sequences, respectively. We propose that the MSA-2 protein is encoded by two highly divergent groups of alleles, with limited additional polymorphism displayed within each group.

Amino Acid Sequence↗
PubMed2026

Mast cell leukemia with complex genomic alterations in an elderly patient with prior hematologic and solid malignancies: a case report.

INTRODUCTION: Mast cell leukemia (MCL) is the rarest and most aggressive variant of systemic mastocytosis (approximately 1% of cases), with a median survival of under 2 years. Diagnosis requires &#x2265;20% atypical mast cells in the marrow aspirate, and the disease frequently overlaps with myeloid neoplasms. CASE PRESENTATION: An 86-year-old man with paranasal sinus diffuse large B-cell lymphoma in remission since 2017 after R-CHOP and methotrexate, and prostate adenocarcinoma treated in 2019, presented with acute pancytopenia, presumed to represent lymphoma relapse. Serum tryptase exceeded 11 999&#xa0;ng/mL; the aspirate showed 20% pleomorphic mast cells (CD117+, weak CD25, CD2-), confirming aleukemic MCL. Formal CMML criteria could not be confirmed due to the unavailability of monocyte differential data; however, the findings raised suspicion for an associated myeloid neoplasm, with SM with an associated hematological neoplasm remaining an alternative classification. Karyotyping was normal; next-generation sequencing revealed pathogenic variants in TP53, RB1, DAXX, ASXL1, TET2, and SRSF2, and a rare extracellular-domain KIT p.D419del. He declined inpatient midostaurin, deteriorated rapidly, and died 2 weeks later. CLINICAL DISCUSSION: This case illustrates a therapy-related MCL (plausible but unconfirmed given the non-leukemogenic profile of methotrexate and the focal nature of prostate stereotactic body radiation therapy) with a suspected associated myeloid neoplasm and complex pathogenic mutations. The KIT p.D419del extracellular domain variant is a rare non-D816V mutation; the canonical D816V was not detected on NGS, though the presence of a low-variant allele fraction D816V cannot be fully excluded due to assay sensitivity. Despite midostaurin, the disease remained aggressive. CONCLUSION: Persistent unexplained cytopenias warrant heightened suspicion of MCL, and comprehensive genomic profiling clarifies diagnosis, distinguishes overlapping myeloid disease, and informs prognosis in this aggressive, refractory neoplasm.

case report↗
PubMed1992

Primary central nervous system lymphomas--an update.

Primary CNS lymphomas (PCNSL), until recently representing about 1% of all brain tumors, show dramatically increased incidence both in high-risk groups (immunocompromised, AIDS) and in the general population. They are extranodal diffuse non-Hodgkin's lymphomas, the morphology and classification of which are identical to those of systemic lymphomas, although PCNSL show different biological behavior and diagnosis according to the New Working Formulation and updated Kiel classification may be difficult. The majority are large B cell variants of high-grade malignancy; low-grade subtypes and T cell lymphomas are rare. Sixty per cent occur in the supratentorial space (hemispheres, periventricular) and 12% in the posterior fossa; 30% are multiple (50%-70% in AIDS). PCNSL show a male preponderance with a peak incidence in the 5th-7th decade (3rd-4th in AIDS). The duration of diffuse or focal clinical symptoms averages 1-2 months. Computed tomography and magnetic resonance imaging scans show single or multiple or diffuse, often typical lesions. Diagnosis is achieved by evaluation of stereotactic biopsy material or cerebrospinal fluid cytology using immunocytological markers. Current therapy in immunocompetent patients, radiation plus corticosteroids and pre- or postradiation polychemotherapy, shows response rates of 85% with a median survival of 17-44 months, a prognosis similar to that for glioblastoma. Meningeal PCNSL is treated with intrathecal methotrexate or cytosine arabinoside. Transliquoral seeding of PCNSL is frequent, distant metastases occurring in 6%-8%. Therapy of AIDS-related PCNSL makes use of radiation and corticosteroids, and rarely of chemotherapy. The pathogenesis of PCNSL is unknown, but Epstein-Barr virus may be a contributory factor.

Brain Neoplasms↗
PubMed1990

C7 reference typing and nomenclature recommendations.

The results of reference typing for C7 are presented and discussed. It appears that the present literature is using consistent nomenclature except that it was not possible to distinguish between the European C7-3 allele and Japanese C7-6. Oriental populations have both a higher frequency of variants and a greater variety of variants than Caucasian populations. Some samples with complex patterns defied classification, and it is speculated that these may be from persons with duplicated C7 genes. It is recommended that no change to the present system of nomenclature be made before a more detailed molecular understanding of the system is achieved.

Complement C7↗
PubMed1992

Cluster headache.

In this article we describe the clinical features, natural history, and clinical variants of cluster headaches, following the modern International Headache Society classification of cluster headaches in its two types: episodic and chronic. The basic pathophysiology is considered to be the trigeminal vascular system, the common final pain pathway, with pain initiated in a cyclical fashion by disordered central hypothalamic pacemaker. Oxygen, rapidly acting ergotamine, or dihydroergotamine preparations serve as abortive treatment of acute attacks; various pharmacotherapeutic options and combination therapies aid in the prophylaxis of cluster headache; and trigeminal radio frequency gangliorhizolysis is a very useful surgical approach in patients with chronic cluster headache who are resistant to medical treatment.

Cluster Headache↗