1/16. Overlap of dyskeratosis congenita with the Hoyeraal-Hreidarsson syndrome.X-linked dyskeratosis congenita (DKC) is characterized by mucosal leukoplakia and ulcerations, skin abnormalities, nail dystrophy, and pancytopenia. Hoyeraal-Hreidarsson syndrome (HHS) includes intrauterine growth retardation, microcephaly, mental retardation, cerebellar malformation, and pancytopenia. A patient with striking features of both HHS and DKC has a de novo mutation in the DKC1 gene, known to be responsible for DKC. HHS may be a severe form of DKC, in which affected individuals die before characteristic mucocutaneous features develop.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
2/16. dyskeratosis congenita: report of a case.dyskeratosis congenita is a rare multisystem condition involving mainly the ectoderm. It is characterized by a triad of reticular skin pigmentation, nail dystrophy and leukoplakia of mucous membranes. Oral and dental abnormalities may also be present. Complications are a predisposition to malignancy and bone marrow involvement with pancytopenia. The case of a 14-year-old girl is described who presented with several of the characteristic systemic features of this condition, together with the following oral features: hypodontia, diminutive maxillary lateral incisors, delayed dental eruption, crowding in the maxillary premolar region, short roots, poor oral hygiene, gingival inflammation and bleeding, alveolar bone loss, caries and a smooth atrophic tongue with leukoplakia. Although this condition is rare, dental surgeons should be aware of the dental abnormalities that exist and the risk of malignant transformation within the areas of leukoplakia.- - - - - - - - - - ranking = 26.582413093778keywords = mucous membrane, membrane (Clic here for more details about this article) |
3/16. One novel and two recurrent missense DKC1 mutations in patients with dyskeratosis congenita (DKC).X-linked dyskeratosis congenita (DKC) is a progressive multisystem disorder most severely affecting tissues with a high cellular turnover such as skin, mucous membranes, and blood. Most patients die of bone marrow failure, although the chances of succumbing to various types of cancer and pulmonary disease are also high. DKC is caused predominantly by missense mutations in the DKC1 gene linked to Xq28. Some of the clinical features are reminiscent of premature ageing and this agrees with recent indications that DKC could be a telomere maintenance disorder. There is considerable variability in the type, severity, and age at onset of the various anomalies. Recognition of this has increased with the finding that patients with Hoyeraal-Hreidarsson syndrome (HHS) who exhibit severe neurological problems in addition to early-onset pancytopenia, also bear mutations in the DKC1 gene. For these reasons, and compounded by the range of mutations, phenotype-genotype correlations and accurate assessments of prognosis have not been possible. To complement the present data, we here report on three new cases of DKC and their mutations. One is a novel mutation in the exon 3 (K43E). The other two represent a frequently recurring mutation in exon 11 (A353V) and a less frequently recurring mutation in the exon 3 (T49M).- - - - - - - - - - ranking = 26.582413093778keywords = mucous membrane, membrane (Clic here for more details about this article) |
4/16. Hereditary benign intraepithelial dyskeratosis: Report of two cases with prominent oral lesions.Hereditary benign intraepithelial dyskeratosis is a rare autosomal dominant disorder of the oral and ocular mucosa initially described in the Haliwa-Saponi Native American tribe of north carolina. We describe 2 sisters with the characteristic oral and ocular findings. This entity should be distinguished from several other diseases that cause white lesions in the mouth including white sponge nevus.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
5/16. DKC1 gene mutation in a Taiwanese kindred with X-linked dyskeratosis congenita.dyskeratosis congenita (DKC) is a rare inherited disease characterized by the triad of abnormal skin pigmentation, nail dystrophy, and mucosal leukoplakia. Recent studies demonstrated mutations in the DKC1 gene encoding a protein named dyskerin, which is a component of human telomerase. In addition to the hypothesized function of pseudouridination in rRNA biosynthesis, ribosomal subunit assembly, and/or centromere/ microtubule binding, lower levels of telomerase activity in cells from patients with X-linked DKC have been observed. We report the mutation analysis of a Taiwanese family with X-linked DKC. The patient was a 19-year-old man who presented with progressive reticulate hyperpigmentation, nail dystrophy, alopecia, leukoplakia of the tongue, and pancytopenia. He died of enterocolitis and escherichia coli sepsis at the age of 20 years. Only his mother's dna was available for mutation analysis, which revealed a nucleotide transition of C to T (1058 C --> T), a hotspot mutation in DKC, resulting in an amino acid change from alanine to valine (A353V) in the DKC1 gene. Recent advances in the research of telomerase and its implications in the human aging process and cancer are discussed.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
6/16. Treatment of dyskeratosis congenita with granulocyte-macrophage colony-stimulating factor and erythropoietin.dyskeratosis congenita (DC) is a rare inherited disorder characterized by reticulate skin pigmentation, nail dystrophy, mucosal leucoplakia, and bone marrow failure. pancytopenia is difficult to manage in patients with this disorder. We describe a 13-month-old-boy who presented with reticulate skin lesions, paleness, and hepatosplenomegaly. anemia and leukopenia developed by the age of 43 months. The patient was treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) (5 microg/kg/d, subcutaneously) for 19 months and erythropoietin (150 U/kg 3 days in a week, subcutaneously) for 8 months, with excellent neutrophil and hemoglobin response. Recurrent infections were not developed after starting GM-CSF, and packed red blood cell transfusion was not given to the patient after starting erythropoietin. GM-CSF combined with erythropoietin may be used in the treatment of bone marrow failure in patients with DC without an HLA-identical donor.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
7/16. dyskeratosis congenita associated with three malignancies.dyskeratosis congenita is a rare inheritable disorder characterized by abnormalities of the skin, nails and oral mucosa. Aplastic anaemia resulting from bone marrow hypoplasia is a frequent cause of death. Squamous cell carcinoma developing from leukoplakia and visceral malignancies are other complications of the disease. We report here a case of dyskeratosis congenita in a man who developed three neoplasias of different systems over a period of many years. Squamous cell carcinoma and gastric adenocarcinoma manifested 17 years after the man was diagnosed with Hodgkin's disease.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
8/16. Further delineation of the congenital form of X-linked dyskeratosis congenita (Hoyeraal-Hreidarsson syndrome).Hoyeraal-Hreidarsson syndrome represents a severe variant of dyskeratosis congenita (Zinsser-Cole-Engman syndrome). This X-linked recessive, progressive, multisystemic disorder reported so far in 12 pedigrees is characterised by intrauterine growth retardation, microcephaly, cerebellar hypoplasia, mental retardation, progressive combined immune deficiency and aplastic anaemia. Mutations in the DKC1gene on Xq28 have been identified in the X-linked form of dyskeratosis congenita and in some Hoyeraal-Hreidarsson syndrome patients. We report on two sibs and two other unrelated patients with the striking clinical features of Hoyeraal-Hreidarsson syndrome. Noticeably, all four had early digestive problems, with chronic, bloody diarrhoea and feeding problems causing one of the most difficult problems in the supportive treatment of this uniformly lethal condition. Pathological changes in the proliferative compartment of the digestive mucosa included alterations of the glandular architecture and focal rarefaction of the glands. This aspect seems consistent with altered telomerase function associated with a dyskerin mutation which may decrease the proliferative capacity of digestive epithelial cells. A missense mutation 146 C-->T (Thr49Met) in the DKC1gene was found in two unrelated patients, whereas mutation screening was negative for one single case. The absence of mutations of the DKC1gene in patients with Hoyeraal-Hreidarsson syndrome emphasises the probable implication of one or more other loci.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
9/16. Identification of a novel mutation and a de novo mutation in DKC1 in two Chinese pedigrees with dyskeratosis congenita.dyskeratosis congenita (DKC) is a rare and fatal congenital syndrome characterized by the triad of reticular skin pigmentation, nail dystrophy and mucosal leukoplakia, and the predisposition to bone marrow failure and malignancies. Mutations in DKC1 gene encoding dyskerin are responsible for the X-linked dyskeratosis congenita. Here we report mutation analysis of two Chinese pedigrees with dyskeratosis congenita. The 15 coding exons of DKC1 and their flanking regions were amplified from genomic dna by PCR. dna sequencing and restriction endonuclease digestion were used for mutation detection. Transition mutation of 1226C-->T (P409L) found in the first pedigree is a novel mutation. In the second pedigree, the proband's mother phenotypically normal carried a de novo transition mutation of 1058C-->T (A353 V) in one allele, and transmitted the mutant allele to her two sons who had typical manifestations of dyskeratosis congenita.- - - - - - - - - - ranking = 1keywords = mucosa (Clic here for more details about this article) |
10/16. dyskeratosis congenita vs. chronic graft versus host disease: report of a case and a review of the literature.dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome characterized by the triad of reticular pigmentation of the skin, nail dystrophy, and mucosal leukoplakia. DC is often associated with severe pancytopenia, and bone marrow failure is the principal cause of early mortality. Malignant transformation of mucosal leukoplakias may also occur. Rarely, aplastic anemia precedes the other clinical manifestations of the disease. We present a case of a 13-year-old boy who was diagnosed at age four with idopathic aplastic anemia, was treated successfully with an allogeneic bone marrow transplant, then subsequently developed skin, nail, and tongue lesions. While the initial impression was chronic graft-versus-host disease, additional work-up confirmed the diagnosis of DC.- - - - - - - - - - ranking = 2keywords = mucosa (Clic here for more details about this article) |
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