Search results for "mutation."
showing 10 items of 2808 documents
Birt–Hogg–Dubé Syndrome: An Update
2012
Birt-Hogg-Dube syndrome is a rare autosomal dominant genodermatosis that is characterized by the presence of fibrofolliculomas and/or trichodiscomas, pulmonary cysts, spontaneous pneumothorax, and renal tumors. The most common histological types found in renal tumors from patients with the syndrome are oncocytoma-chromophobe carcinoma hybrids and pure forms of chromophobe carcinoma, oncocytic carcinoma, and clear cell or papillary cell carcinoma. The syndrome is linked to mutations in the FLCN gene, which encodes folliculin and is preferentially expressed in the skin, kidney, and lung. The syndrome can exhibit a high degree of clinical variability, and the skin lesions that are a warning si…
Usefulness of immunohistochemical staining for p53 in the prognosis of breast carcinomas: correlations with established prognosis parameters and with…
1995
Mutations of the p53 gene often result in the overexpression of p53 protein. Previous studies have suggested that the function of p53 and its mutant protein forms may be linked with the disease course of patients with a breast carcinoma. In the present study, we tested 462 primary breast carcinomas for the presence of p53 antigen using immunohistochemical methods employing antibodies against the clone, DO-1. These tumors were also immunohistochemically stained using the monoclonal antibody, MIB-1, in order to demonstrate the presence of Ki67. Comparison of the presence of p53 with other prognostic parameters revealed highly significant negative correlations with estrogen- and progesterone-r…
Identification of a Novel BRCA1 Alteration in Recurrent Melanocytoma Resulting in Increased Proliferation
2020
Abstract Primary meningeal melanocytomas are rare tumors of the central nervous system. Although they are considered benign neoplasms, some reports describe recurrent rates up to 45%. Little is known about their genetic and epigenetic landscape because of their infrequency. Even less has been described about markers with prognostic value. Here we describe a patient who developed a primary meningeal melanocytoma, suffered 3 recurrences in a period of 6 years and died of the tumor. The genetic and epigenetic changes explored confirmed GNAQ mutation as an initiating event. We found an epigenetic alteration of GSTP1, a feature that has recently been described in meningiomas, from the beginning …
Metastasizing anaplastic ependymoma in an adult. Chromosomal imbalances, metabolic and gene expression profiles
2009
Absence of p53 gene mutations in hepatocarcinomas from a Mediterranean area of Spain
1999
The incidence of p53 gene abnormalities in human hepatocellular carcinoma (HCC) varies in different geographical areas, being higher in regions where hepatitis virus infection and dietary exposure to aflatoxin B1 are the most common aetiological agents. These mutations are less frequently encountered in Europe, although some studies have reported p53 protein overexpression in up to 45% of cases analysed. We have analysed 129 tumour samples of primary malignant hepatic neoplasms recovered from paraffin blocks processed in two pathology laboratories in a Mediterranean area of Spain (Valencia and Gerona). Among 14 cases in which p53 immunohistochemistry expression proved positive, 5 stained in…
Genetic disorders of connective tissues
1991
Due to the growing knowledge of structure and function of extracellular matrix proteins, congenital abnormalities of connective tissues are identified or suspected in an increasing number of clinical disorders. In osteogenesis imperfecta and two subtypes of Ehlers-Danlos syndrome, the affected matrix proteins were identified and mutations in the corresponding genes (procollagen type I and type III, respectively) could be demonstrated. Some forms of chondrodysplasia were shown to be associated with mutations in the gene encoding for the cartilage-specific collagen (type II). In part, the clinical phenotype is determined by the tissue-specific distribution of these collagens. However, the cor…
Presenilin-1 Mutations Are a Cause of Primary Lateral Sclerosis-Like Syndrome
2021
6 páginas, 2 figuras
T2 mapping of the peritumoral infiltration zone of glioblastoma and anaplastic astrocytoma.
2021
Purpose To characterise peritumoral zones in glioblastoma and anaplastic astrocytoma evaluating T2 values using T2 mapping sequences. Materials and methods In this study, 41 patients with histopathologically confirmed World Health Organization high grade gliomas and preoperative magnetic resonance imaging examinations were retrospectively identified and enrolled. High grade gliomas were differentiated: (a) by grade, glioblastoma versus anaplastic astrocytoma; and (b) by isocitrate dehydrogenase mutational state, mutated versus wildtype. T2 map relaxation times were assessed from the tumour centre to peritumoral zones by means of a region of interest and calculated pixelwise by using a fit m…
Clinical spectrum of BICD2 mutations.
2020
Background and purpose Mutations in the BICD2 gene cause autosomal dominant lower extremity-predominant spinal muscular atrophy 2A (SMALED2A), a condition that is associated with a specific pattern of thigh and calf muscle involvement when studied by magnetic resonance imaging (MRI). Patients may present minor clinical sensory impairment, but objective sensory involvement has yet to be demonstrated. Methods We collected clinical data from 11 patients from five different families carrying mutations in BICD2. Genetic diagnosis was achieved using gene panel testing and skin biopsies were taken from two patients to study the epidermal nerve fiber density. Results In the studied patients, three …