1/14. Combined immunodeficiency associated with increased apoptosis of lymphocytes and radiosensitivity fibroblasts.Severe immunodeficiency characterized by lymphopenia was found in two siblings, one of whom was examined in detail. The calcium flux, pattern of tyrosine phosphorylation of proteins, and interleukin 2 (IL-2) production and proliferation in response to mitogens suggested that the peripheral blood T cells activated normally. The peripheral blood T cells were shown to have an activated phenotype with increased expression of CD45RO and CD95/Fas. Increased spontaneous apoptosis occurred in unstimulated lymphocyte cultures. The elevated apoptosis was not due to alterations in expression or to mutations in Bcl-2, Bcl-X(L), or Flip, nor could the spontaneous apoptosis be prevented by blocking Fas, suggesting that it was independent of Fas signaling. This is the first inherited combined immunodeficiency associated with impaired lymphocyte survival. fibroblasts derived from the patient showed appreciable radiosensitivity in clonal assays, but apoptosis was not elevated. Our results show that the fibroblasts represent a new radiosensitive phenotype not associated with cell cycle checkpoint defects, V(D)J recombination defects, or elevated chromosome breakage. We suggest that the affected gene plays a role in an undetermined damage response mechanism that results in elevated spontaneous apoptosis in lymphoid cells and radiosensitivity in fibroblasts.- - - - - - - - - - ranking = 1keywords = breakage (Clic here for more details about this article) |
2/14. Juvenile rheumatoid arthritis-like polyarthritis in nijmegen breakage syndrome.nijmegen breakage syndrome (NBS) is a rare autosomal recessive disease (8q21) from the family of the genetically determined chromosomal instability syndromes. The disorder is characterized by microcephaly, growth retardation, immunodeficiency, and high incidence of cancer. Several noninflammatory anomalies of the musculoskeletal system have been described in patients with this syndrome. We describe an Argentinian girl with all the clinical, immunological, and cytogenic characteristics described for NBS plus a juvenile rheumatoid arthritis-like syndrome. To our knowledge this is the first report of a patient with the NBS who presented with a symmetric chronic polyarthritis resembling JRA.- - - - - - - - - - ranking = 125.9215999738keywords = breakage syndrome, breakage (Clic here for more details about this article) |
3/14. T-cell prolymphocytic leukemia with autoimmune manifestations in nijmegen breakage syndrome.nijmegen breakage syndrome (NBS) is characterized by growth retardation, microcephaly, mental retardation, immunodeficiency, and predisposition to malignancies, especially B-cell lymphomas. In contrast, leukemia is rare. A 23-year-old NBS patient presented with anemia, thrombocytopenia, and hyperlymphocytosis. The diagnosis of T-cell prolymphocytic leukemia (T-PLL) was confirmed by cytological and immunological assays (TdT(-), CD2( ), CD5( ), CD3m, and CD7( )). Biological assays also showed a hemolytic anemia and a clotting factor V decrease. The patient was first treated by methylprednisone for 3 weeks. During this period the lymphocyte count decreased. The simultaneous normalization of the hemolysis and of factor V suggested that both could be related to T-PLL. Since T-PLL is refractory to conventional therapies with a poor prognosis, an intensive chemotherapy such as 2'-deoxycoformycin with anti-CDw52 monoclonal antibodies is usually favored. In the present case, however, because of the specific context (i.e., NBS-induced immunodepression, severe hemolytic anemia, and acquired factor v deficiency), he received pentostatin weekly during 1 month and in maintenance during 6 months. At last follow-up (7 months) he showed a persistent control of the lymphocytosis with no side effect.- - - - - - - - - - ranking = 125.9215999738keywords = breakage syndrome, breakage (Clic here for more details about this article) |
4/14. nijmegen breakage syndrome diagnosed as Fanconi anaemia.BACKGROUND: Fanconi anaemia (FA) and nijmegen breakage syndrome (NBS) are rare chromosomal instability disorders with overlapping clinical features. It has recently been shown that, like FA, NBS is also associated with increased chromosomal sensitivity to DNA cross-linking agents. PROCEDURE: We report a family that was initially diagnosed with FA on the basis of increased sensitivity to DNA cross-linking agents. They were atypical in that there were associated severe infection problems. In view of these features we performed immune function studies together with molecular analysis of the FA genes and subsequently the NBS1 gene. RESULTS: Two children in the kindred have died, one from sepsis, and the other with a plasma cell malignancy. A third child underwent bone marrow transplantation because of recurrent infections. All affected members had severe immunological abnormalities. The genetic defect was shown to be a novel mutation in the NBS1 gene, so the diagnosis was revised to that of NBS. CONCLUSIONS: This family illustrates the importance of awareness of the lack of specificity of DNA cross-linking agent tests for FA, particularly in situations where the clinical features are atypical. In addition, one of the cases represents the first use of bone marrow transplantation for NBS that we are aware of; this treatment may have a future role for other patients with the syndrome.- - - - - - - - - - ranking = 125.9215999738keywords = breakage syndrome, breakage (Clic here for more details about this article) |
5/14. Unusual T cell clones in a patient with nijmegen breakage syndrome.The rare autosomal recessive nijmegen breakage syndrome is characterised by severe immunodeficiency, microcephaly associated with mental retardation, and typical chromosomal rearrangements in peripheral T lymphocytes. This syndrome, though similar to ataxia telangiectasia, does not exhibit the neurological and cutaneous signs of this disorder. We report here the first patient with Nijmegen breakage syndrome ascertained in france. Chromosome analysis detected, in addition to the specific aberrations, two clonal T cell proliferations which do not involve the usual bands 14q11.2 and 14q32.1.- - - - - - - - - - ranking = 151.10591996856keywords = breakage syndrome, breakage (Clic here for more details about this article) |
6/14. A disease with immune deficiency, skin abscesses, pancytopenia, abnormal bone marrow karyotype, and increased sister chromatid exchanges: an autosomal recessive chromosome instability syndrome?A 19-year-old girl is described with microcephaly, short stature, mental retardation, pigmentation of the skin, and recurrent skin abscesses over the whole body. Her elder brother and sister both showed growth and developmental retardation, microcephaly, and anemia. Both died during childhood. Their parents were first cousins. Laboratory studies of the proband revealed hyperchromic erythrocytes with an increased HbF content, thrombocytopenia, an impaired mitogenic response of the PHA-stimulated lymphocytes, and partial impairment of humoral and cellular immunity. She developed pancytopenia in the terminal stage of the disease. Cytogenetic studies of the bone marrow revealed 46,XX, 15p , -18, mar karyotype, increased chromosomal aberrations and sister chromatid exchanges, in cultured lymphocytes and skin fibroblasts. She died at age 20. Thus, the disorder in the patient was deduced as an unclassified chromosomal breakage syndrome with an apparently autosomal recessive inheritance.- - - - - - - - - - ranking = 25.18431999476keywords = breakage syndrome, breakage (Clic here for more details about this article) |
7/14. A chromosomal breakage syndrome with profound immunodeficiency.The chromosomal breakage syndromes--ataxia-telangiectasia, Fanconi's anemia, and Bloom's syndrome--are associated with growth failure, neurologic abnormalities, immunodeficiency, and an increased incidence of malignancy. The relationship between these features is unknown. We recently evaluated a 21-year-old female with more severe chromosomal breakage, immunodeficiency, and growth failure than in any of the mentioned disorders. As of November 1985, the patient remains clinically free of malignancy. At age 18, the patient's weight was 22.6 kg (50th percentile for seven years), height was 129 cm (50th percentile for eight years), and head circumference was 42 cm (50th percentile for six months). Laboratory studies demonstrated a marked decrease in both B and T cell number and function. The peripheral blood contained 400 to 900 lymphocytes/microL with 32% T11 cells, 17% T4 cells, and 21% T8 cells. The proliferative responses to phytohemagglutinin (PHA), pokeweed mitogen, and concanavalin a were less than 10% of control. There were 1% surface IgM positive cells, and serum IgG was 185 mg/dL, IgM 7 mg/dL, IgA 5 mg/dL. In lymphocyte cultures stimulated with the T cell mitogens PHA, phorbol ester, and interleukin 2, 55% of the banded metaphases demonstrated breaks or rearrangements. The majority of the breaks involved four fragile sites on chromosomes 7 and 14, 7p13, 7q35, 14q11, and 14q32. These are the sites of the genes for the T cell-antigen receptor and the immunoglobulin heavy chain and are sites of gene rearrangement in lymphocyte differentiation. Epstein-Barr virus stimulated B cells and fibroblast cultures also demonstrated a high incidence of breaks, but the sites were less selective. These findings suggest that the sites of chromosomal fragility in the chromosomal breakage syndromes may be informative and that factors other than the severity of the immunodeficiency or the high incidence of chromosomal damage may contribute to the occurrence of malignancy in the chromosomal breakage syndromes.- - - - - - - - - - ranking = 177.29023996332keywords = breakage syndrome, breakage (Clic here for more details about this article) |
8/14. ATFresno: a phenotype linking ataxia-telangiectasia with the nijmegen breakage syndrome.This report describes twin girls with typical features of ataxia-telangiectasia, including increased alpha-fetoprotein, radio-resistant DNA synthesis, characteristic chromosome abnormality, and immunodeficiency. They have, in addition, microcephaly and mental retardation. Complementation studies were performed utilizing sendai virus--mediated fusion of fibroblast cell lines. Complementation was observed with patients in ataxia-telangiectasia complementation groups A, C, and E but not with the cell line from a patient with the nijmegen breakage syndrome, in which patients have microcephaly, radio-resistant DNA synthesis, chromosome aberrations, and immunodeficiency but lack ataxia and telangiectasia. These data suggest that the nijmegen breakage syndrome and the patients described here are not genetically distinct entities but form a spectrum of one disorder.- - - - - - - - - - ranking = 151.10591996856keywords = breakage syndrome, breakage (Clic here for more details about this article) |
9/14. Differential expression of the ICF (immunodeficiency, centromeric heterochromatin, facial anomalies) mutation in lymphocytes and fibroblasts.fibroblasts from a patient with ICF syndrome were grown in the presence of excess of nucleotides, in media with different amounts of folic acid, and with caffeine in an attempt to induce the chromosomal anomalies observed in lymphocytes. We induced despiralisation and breakages in the centromeric heterochromatin of chromosomes 1 and 16 but not associations and multibranching. We suggest that the absence of the major chromosomal anomalies in fibroblasts from patients with ICF might be the result of both a longer G2 in these cells and differential patterns of interphase heterochromatin associations in the two tissues.- - - - - - - - - - ranking = 1keywords = breakage (Clic here for more details about this article) |
10/14. Further delineation of the nijmegen breakage syndrome.We report on five independent families with a chromosome instability disorder that earlier had been called the nijmegen breakage syndrome (NBS). These families, two from the netherlands and three from czechoslovakia, had a total of eight patients, five of whom are still alive. The main clinical manifestations were microcephaly, short stature, a "bird-like" face, immunological defects involving both the humoral and cellular system. In four of the five living patients it has been possible to study the chromosomes of cultured lymphocytes. The basic karyotype in these patients were normal, but in 17% to 35% of the metaphases rearrangements were found, preferentially involving chromosomes 7 and/or 14 at the sites 7p13, 7q34, and 14q11. The chromosomes of all five living patients were very sensitive to ionizing radiation. In addition, the DNA synthesis in their cultured lymphocytes and fibroblasts was more resistant to x-rays than in cells from controls. The NBS shares a number of important features with ataxia telangiectasia (AT). Both syndromes are characterized by the occurrence of typical rearrangements of chromosomes 7 and/or 14, cellular and chromosomal hypersensitivity to X-irradiation, radioresistance of dna replication and immunodeficiency. However, there are also obvious differences: NBS patients have microcephaly but neither ataxia nor telangiectasia, and in contrast to the situation in AT the alpha-fetoprotein level in their serum is normal.- - - - - - - - - - ranking = 125.9215999738keywords = breakage syndrome, breakage (Clic here for more details about this article) |
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