Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Variant classification”

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

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

At least 433 records · Page 24Linked to original sources
PubMed1994

The hereditary palmoplantar keratoses: an updated review and classification.

The palmoplantar keratoses (PPKs) comprise a heterogeneous group of disorders of keratinization, which can be subdivided into hereditary and acquired forms. Many authors have attempted to classify the hereditary forms, and most classifications have been based on the morphology, distribution, associated symptoms and mode of inheritance. Subsequently, many new forms have been recognized, and what were previously considered to be distinct types have been shown to be variants of a single type, both of which limit the usefulness of previous classifications. Hence, we propose a new, updated classification, which enables accurate diagnosis of these disorders.

Humans↗
PubMed1999

Inherited prion disease with an alanine to valine mutation at codon 117 in the prion protein gene.

A large English family with autosomal dominant segregation of presenile dementia, ataxia and other neuropsychiatric features is described. Diagnoses of demyelinating disease, Alzheimer's disease, Creutzfeldt-Jakob disease (CJD) and Gerstmann-Sträussler-Scheinker syndrome have been attributed to particular individuals at different times. An Irish family, likely to be part of the same kindred, is also described, in which diagnoses of multiple sclerosis, dementia, corticobasal degeneration and new variant CJD have been considered in affected individuals. Molecular genetic studies have enabled the classification of this disease at the molecular level as one of the group of inherited prion diseases, with the substitution of valine for alanine at codon 117 of the prion protein gene (PRNP). Only three other kindreds have been described world-wide with this mutation and only limited phenotypic information has been reported. Here we describe the phenotypic spectrum of inherited prion disease (PrPA117V). The diversity of phenotypic expression seen in this kindred emphasizes the logic of molecular classification of the inherited prion diseases rather than classification by specific clinicopathological syndrome. Indeed, inherited prion disease should be excluded by PRNP analysis in any individual presenting with atypical presenile dementia or neuropsychiatric features and ataxia, including suspected cases of new variant CJD.

Adult↗
PubMed2000

[Large B-cell lymphomas: variants and entities].

Large B-cell neoplasms represent one of the most frequent groups of non-Hodgkin-lymphomas (30-40%). They are characterized by an aggressive clinical course. These lymphomas may evolve either de novo or secondary during the course of a less aggressive lymphoma. In addition to primary nodal, a primary extranodal manifestation is rather common. The neoplastic cells, even within one given case, show a broad morphological spectrum. Several findings of the last two decades have revealed that the large B-cell lymphomas represent an inhomogeneous group. This fact has been taken into account by the new WHO classification of malignant lymphomas. There are two groups identified, that of the variants and that of the subtypes. The various variants (centroblastic, immunoblastic, anaplastic, T-cell/histiocyte-rich) correspond to lymphomas without reproducible discriminating criteria lacking characteristic clinical, immuno-phenotypical and genetic findings. In contrast, the primary mediastinal, the intravascular, the primary effusion and primary central nervous system lymphomas represent distinct disease entities. A number of recently described large cell lymphoma types, i.e. plasma-blastic, ALK-positive and primary gastric, are included in the classification, their designation as distinct entities is still under discussion.

Genotype↗
PubMed1993

Human prion diseases (spongiform encephalopathies).

Prion diseases (spongiform encephalopathies) in humans are Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), and kuru. Clinically, they are characterized by an inexorably progressing neurological illness with dementia and ataxia as the most prominent signs. The classical neuropathological changes are limited to the central nervous system and consist of spongiform degeneration, amyloid plaques, astrocytic gliosis, and nerve cell loss. The human spongiform encephalopathies, which for many years were considered neurodegenerative disorders of unknown etiology, were finally recognized as transmissible diseases similar to scrapie in sheep in the late 1960's. The infectious agent appears to consist of protein devoid of functional nucleic acid and has been termed prion to distinguish it from viruses. The prion hypothesis has gained wide acceptance through the finding that mutations of the prion protein gene are associated with heritable human prion disease. Different mutations appear to cause prion disease with a distinct pattern of clinical and pathological features in a great number of families. Certain mutations of the PrP gene have been shown to be associated with clinical and neuropathological changes not typical of any variant of human prion disease known to date. A new classification of prion diseases based on the molecular biology and biochemistry of the prion protein is likely to emerge.

Animals↗
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↗
PubMed1997

Artificial neural network analysis of noisy visual field data in glaucoma.

This paper reports on the application of an artificial neural network to the clinical analysis of ophthalmological data. In particular a 2-dimensional Kohonen self-organising feature map (SOM) is used to analyse visual field data from glaucoma patients. Importantly, the paper addresses the problem of how the SOM can be utilised to accommodate the noise within the data. This is a particularly important problem within longitudinal assessment, where detecting significant change is the crux of the problem in clinical diagnosis. Data from 737 glaucomatous visual field records (Humphrey Visual Field Analyzer, program 24-2) are used to train a SOM with 25 nodes organised on a square grid. The SOM clusters the data organising the output map such that fields with early and advanced loss are at extreme positions, with a continuum of change in place and extent of loss represented by the intervening nodes. For each SOM node 100 variants, generated by a computer simulation modelling the variability that might be expected in a glaucomatous eye, are also classified by the network to establish the extent of noise upon classification. Field change is then measured with respect to classification of a subsequent field, outside the area defined by the original field and its variants. The significant contribution of this paper is that the spatial analysis of the field data, which is provided by the SOM, has been augmented with noise analysis enhancing the visual representation of longitudinal data and enabling quantification of significant class change.

Diagnosis, Computer-Assisted↗
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↗
PubMed2001

Transmissible spongiform encephalopathies in Australia.

The Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR) commenced surveillance in September 1993 as part of the Commonwealth's response to 4 cases of pituitary hormone (gonadotrophin)-associated Creutzfeldt-Jakob disease (CJD). With the passage of time, the Registry has become responsible for ascertaining all human transmissible spongiform encephalopathies (TSE; also known as prion diseases) within Australia since 1970. Included in the spectrum of diseases monitored are classical (sporadic, genetic, and health care acquired) CJD, and variant CJD (vCJD), first reported in 1996 in the United Kingdom. Variant CJD has not yet been diagnosed in Australia. Final classification of persons with suspected human prion disease is based upon all available clinical, investigational and pathological information. Ascertainment methods are diverse and include prompted, half-yearly personal communications from neurologists and neuropathologists, death certificate searches, and morbidity separation coding searches of major hospital, and State and Territory databases. More recently, referral for diagnostic CSF 14-3-3 protein testing (performed by the ANCJDR) has considerably increased prospective notifications of suspect cases. As at September 2001 there were 460 cases on the register; 237 definite cases, 168 probable and 55 incomplete cases awaiting final classification.

Animals↗
PubMed2000

Atypical hairy cell leukemia.

The morphologic differential diagnosis of mature B-cell neoplasms with cytoplasmic projections includes splenic lymphoma with villous lymphocytes and hairy cell leukemia. Although the classification of hairy cell leukemia is not universally recognized, 3 variants have been described, namely, classic, variant, and Japanese variant, each of which has different clinical and immunophenotypic features. Classic hairy cell leukemia is virtually always CD11c(+), CD25(+), and CD103(+). Variant and Japanese variant hairy cell leukemias are usually CD11c(+), always CD25(-), and occasionally CD103(+). Each variant is characteristically CD10(-). We present a case of hairy cell leukemia with a unique immunoprofile in that the cells were CD10(+), CD25(+), and CD103(-), and we review the criteria helpful in differentiating "hairy" B-cell neoplasms. This case emphasizes the variability of hairy cell leukemia and the need to correlate all clinical and pathologic data in reaching a diagnosis.

Aged↗
PubMed2000

Progress in the classification of hematological neoplasms. From REAL to WHO concept

Recent advances in immunology, molecular biology and cytogenetics as well as the development of new diagnostic techniques set out the necessity for the redefinition and reclassification of hematological malignancies. Therefore, WHO in 1995 assigned the Society of Hematopathology and European Association for Hematopathology to create a new classification of these neoplasms. The result of collaborative efforts of leading hematopathologists from both organizations is the World Health Organisation (WHO) classification of hematological neoplasms. WHO classification adopted basic concepts, defined criteria introduced by REAL classification of lymphoid neoplasms and extended them to myeloid, histiocytic and mastocytic neoplasms. WHO classification of hematological neoplasms is represented by a list of disease entities and its variants, opened for inclusion of new entities, updating of diagnostic criteria and changes of nomenclature. The clinical relevance of the proposed entities has been evaluated by the clinicians, members of Clinical Advisory Committee. The proposed classification is a challenge to the clinicians to create new treatment strategy, directed towards particular disease entities. The presentation of WHO classification in our review is limited to myeloid and lymphoid neoplasms.

Journal Article↗
PubMed2002

Evaluation of referrals for genetic investigation of short stature in Hong Kong.

OBJECTIVE: To establish a profile of the causes of apparently unexplained SS in genetic referral center and evaluate the current referral system. METHODS: This was a retrospective database survey on patients who were referred our clinical genetic service from 1988 - 1998 primarily because of SS. We retrieved the study population from our computer database using "short stature"as a search handle and then studied the demographic, clinical and laboratory data from their medical records. RESULTS: Three hundred and fifty-three subjects were referred for genetic evaluation of SS in 1988 - 1998. The mean age of referred subjects was 11.5 years and the female to male ratio was 7.6. All referrals had undergone cytogenetic studies to exclude chromosomal abnormalities, 19% of girls with apparently unexplained short stature had Turner syndrome; at least 47.9% of the study population were normal variants and 25% of the referrals had inadequate information for classification. CONCLUSIONS: Genetic investigation is essential in the management of patients with SS, especially for girls suspected of having Turner syndrome, in which growth hormone treatment has shown to improve final height. We also highlight the inherited causes of short stature, which were often misdiagnosed as benign familial short stature, and discussed the drawbacks of the current referral system.

Child↗
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↗
PubMed1991

[Criteria for evaluating the severity of craniocerebral trauma in children].

The article discusses the total results of multifactorial analysis of observations over 16,000 children with isolated and more than 400 with combined craniocerebral trauma (CCT) in the light of the peculiarities of the child age and the current trends in studying the problem in the Soviet Union and other countries. From these standpoints, the author first gives a clinicomorphological characterization of CCT types in children, deals with the methods and prospects of objectivication of the evaluation of the severity of isolated and combined CCT, extracranial local injuries in polytrauma, totally determining the severity of the general condition and the efficacy and prognosis of the diagnostic and therapeutic measures. Original methods for quantitative evaluation of the degree of severity of the trauma, which were developed in the clinic, are described. A variety of the clinical CCT forms and the possible variants of the concomitant injuries are systematized in a CCT classification approximated maximally to the solution of practical problems under different conditions, including extreme conditions in mass injuries. For this purpose, the author uses conventional designations for the main gradients of the pathophysiological reactions of the child's organism depending on the location and severity of the concrete damages and the general condition, making a coded recording of the diagnosis possible, which makes easier the sorting out and registration of the patients and orientation as regards the order in which aid should be given and the volume of the therapeutic and diagnostic programs with the use of computers. The patients were subjected to general clinical examination and laboratory tests, as well as special methods of examination (radiography, ultrasonic study, angiography, circulography, computed tomography, etc.). Importance was attached to the results of histological study and the reports of the forensic medical examination committee.

Brain Injuries↗
PubMed1989

[The place of echography in the clinical diagnosis of hepatic hemangioma].

On the basis of 104 hemangiomas diagnosed in 81 patients an ultrasound classification of the disease is made which includes four basic variants. Echotomography detects the tumor most successfully in group I (well outlined homogenous hyperechogenisity) while in the other groups it shows a low percentage of correct diagnoses. The average sensitivity of the method is 60.6%. The possibilities of the other basic diagnostic methods are discussed and a scheme for clinical investigation is proposed. Scintigraphy is of no substantial help, computed tomography increases the percentage of the correct diagnoses, angiography and correctly indicated laparoscopy most often end the clinical investigation. The patients with hemangioma are subjected to a prolonged clinical follow up and ultrasound tomography is the best suitable method for this.

Adult↗
PubMed1988

[Artificial arteriovenous anastomoses in reconstructive surgery of arteries with a poor distal vascular bed].

Based on their experience with the operative treatment of 20 patients with acute thrombosis of major arteries of extremities the authors recommend if indicated to combine reconstructive operation on the arteries with the artificial arterio-venous anastomosis. The authors have developed a classification of such associated operations which facilitates choice of their variants dependent on the state of the distal vascular bed.

Adult↗
PubMed1989

Revised classification of posterior fossa cysts and cystlike malformations based on the results of multiplanar MR imaging.

MR and clinical data on 31 patients with posterior fossa CSF collections were analyzed. A clear separation of these patients into classical categories was not possible because of new information obtained from the MR images. We present a new classification of these disorders. The Dandy-Walker malformation, Dandy-Walker variant, and mega-cisterna magna seem to represent a continuum of developmental anomalies of the posterior fossa. A possible embryologic basis for this continuum is suggested. Discrete posterior fossa CSF collections that are clearly separate from the fourth ventricle and vallecula are classified as posterior fossa cysts. Posterior fossa CSF collections that communicate with the fourth ventricle and are associated with cerebellar atrophy are classified as prominent cisterna magna. Both the Dandy-Walker complex and posterior fossa cysts can cause enlargement of the posterior fossa and scalloping of the inner table of the occipital bone. The Dandy-Walker complex presents with seizures, developmental delay, and enlarging head size; it requires CSF diversion when associated with hydrocephalus. Posterior fossa cysts present with symptoms of a posterior fossa mass; they generally require surgical resection. Prominent cisterna magna is a result of degenerative disorders and requires no surgical therapy. This new classification facilitates both diagnosis and therapy of these disorders. MR revealed that disorders previously referred to as the Dandy-Walker malformation, the Dandy-Walker variant, and the mega-cisterna magna actually are not separate entities, but appear to represent steps on a continuum of developmental anomalies of the posterior fossa. Because of this, we suggest a new term, the Dandy-Walker complex, be used to describe this continuum.

Adolescent↗