1/14. Ataxia, ocular telangiectasia, chromosome instability, and Langerhans cell histiocytosis in a patient with an unknown breakage syndrome.An 8 year old boy who had Langerhans cell histiocytosis when he was 15 months old showed psychomotor regression from the age of 2 years. microcephaly, severe growth deficiency, and ocular telangiectasia were also evident. Magnetic nuclear resonance imaging showed cerebellar atrophy. Alphafetoprotein was increased. Chromosome instability after x irradiation and rearrangements involving chromosome 7 were found. Molecular study failed to show mutations involving the ataxia-telangiectasia gene. This patient has a clinical picture which is difficult to relate to a known breakage syndrome. Also, the relationship between the clinical phenotype and histiocytosis is unclear.- - - - - - - - - - ranking = 1keywords = breakage syndrome, breakage (Clic here for more details about this article) |
2/14. Embryonal rhabdomyosarcoma and chromosomal breakage in a newborn infant with possible Dubowitz syndrome.We report on a newborn girl with Dubowitz syndrome (DS) and embryonal rhabdomyosarcoma (ERMS), with multiple chromosomal breakage (MCB). The tumor was resected but recurred in a few months, resulting in the infant's death. Malignancy and chromosomal breakage have been reported previously in DS. However, ERMS has not been reported among the malignant tumors diagnosed in DS. To our knowledge, concurrence of DS, ERMS, and MCB has not been reported previously. This is the first observation of DS in the Arab ethnic group.- - - - - - - - - - ranking = 0.067067131130701keywords = breakage (Clic here for more details about this article) |
3/14. nijmegen breakage syndrome. The International nijmegen breakage syndrome Study Group.BACKGROUND: nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder. NBS-1, the gene defective in NBS, is located on chromosome 8q21 and has recently been cloned. The gene product, nibrin, is a novel protein, which is member of the hMre11/hRad50 protein complex, suggesting that the gene is involved in DNA double strand break repair. AIMS: To study the clinical and laboratory features of NBS as well as the genotype-phenotype relation. methods: Fifty five patients with NBS, included in the NBS registry in Nijmegen were evaluated. The majority of the patients were of eastern European ancestry. Most of them had shown a truncating 5 bp deletion 657-661 delACAAA. Four further truncating mutations have been identified in patients with other distinct haplotypes. RESULTS AND CONCLUSIONS: Essential features found in NBS were microcephaly, usually without severe retardation, typical facial appearance, immunodeficiency, chromosomal instability, x ray hypersensitivity, and predisposition to malignancy. In 40% of the patients cancer was noted before the age of 21 years. Important additional features were skin abnormalities, particularly cafe au lait spots and vitiligo, and congenital malformations, particularly clinodactyly and syndactyly. Congenital malformations, immunodeficiency, radiation hypersensitivity, and cancer predisposition were comprehensible in case of dysfunctioning of dna repair mechanisms. No specific genotype-phenotype relation could be found. patients with the same genotype may show different phenotypes and patients with different genotypes may express the same phenotype. Specific mutations did not lead to specific clinical features.- - - - - - - - - - ranking = 1keywords = breakage syndrome, breakage (Clic here for more details about this article) |
4/14. Clinical presentation and mutation identification in the NBS1 gene in a boy with nijmegen breakage syndrome.nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder which belongs to the group of inherited chromosomal instability syndromes. The clinical characteristics include severe microcephaly, a dysmorphic facies, and immunodeficiency with predisposition to malignancies. While the cellular characteristics of ataxia teleangiectasia (AT) and NBS are similar, the clinical findings are quite distinct. NBS patients show characteristic microcephaly, which is rare in association with AT and they do not develop ataxia and teleangiectasia. Recently, the gene mutated in NBS has been identified. Here we report a 5-year-old Bosnian boy with severe microcephaly. Because of multiple structural aberrations involving chromosomes 7 and 14 typical for AT (MIM 208900) and NBS (MIM 251260), AT was diagnosed. We suggested the diagnosis of NBS because of the boy's remarkable microcephaly, his facial appearance, and the absence of ataxia and teleangiectasia. DNA analysis was performed and revealed that the boy is homozygous for the major mutation (657de15) in the NBS1 gene. This finding confirms the diagnosis of NBS in our patient and offers the possibility to perform a most reliable prenatal diagnosis in a further pregnancy.- - - - - - - - - - ranking = 1keywords = breakage syndrome, breakage (Clic here for more details about this article) |
5/14. 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 = 1keywords = breakage syndrome, breakage (Clic here for more details about this article) |
6/14. rhabdomyosarcoma in nijmegen breakage syndrome: strong association with perianal primary site.nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder resulting from mutations in the NBS1 gene, which encodes for the DNA double strand break repair protein nibrin. NBS is clinically characterized by microcephaly, dysmorphic features, immunodeficiency, and increased susceptibility to malignancy, mainly of lymphoid origin. Here, we describe a 7-year-old girl with NBS who is homozygous for the NBS1 698del4 mutation. She had been diagnosed with perianal rhabdomyosarcoma (RMS) and experienced severe toxicity from chemotherapy. RMS arising perianally is extremely uncommon but has been previously described in two cases with NBS. The strong association of perianal RMS with NBS should, therefore, be considered when confronted with a perianal RMS, as this carries important clinical implications in terms of potential need for therapy modification and follow up investigations. In addition, it suggests a role for the NBS1 gene and the nibrin dependent pathway in the pathogenesis of RMS, especially those arising perianally.- - - - - - - - - - ranking = 1keywords = breakage syndrome, breakage (Clic here for more details about this article) |
7/14. A patient with mutations in DNA Ligase IV: clinical features and overlap with nijmegen breakage syndrome.The clinical phenotype of Ligase IV syndrome (LIG4 syndrome), an extremely rare autosomal recessive condition caused by mutations in the LIG4 gene, closely resembles that of nijmegen breakage syndrome (NBS), and is characterized by microcephaly, characteristic facial features, growth retardation, developmental delay, and immunodeficiency. We report a 4(1/2)-year-old boy who presented with acute T-cell leukemia. The facial gestalt was strongly reminiscent of NBS. The patient died shortly after the onset of treatment for his T-cell leukemia. Subsequent chromosome breakage studies showed a high rate of breakage in a fibroblast culture. Radiosensitivity was assessed by a colony survival assay; the results showed radiosensitivity greater than is typically seen in NBS. mutation screening of the NBS1 gene was negative. Sequencing of the LIG4 gene revealed a homozygous truncating mutation 2440 C>T (R814X). Although this mutation has been previously noted in LIG4 syndrome, this patient is the first reported homozygote for the mutation. In this study, we review the clinical features of this rare syndrome and provide suggestions for differential diagnosis.- - - - - - - - - - ranking = 1.0223557103769keywords = breakage syndrome, breakage (Clic here for more details about this article) |
8/14. A case report of a patient with microcephaly, facial dysmorphism, mitomycin-c-sensitive lymphocytes, and susceptibility to lymphoma.We report on a 17-year-old boy with a unique lymphocyte mitomycin-C (MMC)-sensitive chromosomal breakage syndrome. He had failure to thrive, and has microcephaly, slight facial dysmorphism, and constitutional short stature but no other phenotypic or hematological manifestations of fanconi anemia (FA). He developed B-cell lymphoma of the neck, which was treated with standard doses of alkylating agents. Major side effects related to chemotherapy did not occur. Normal erythrocyte corpuscular volume, MMC-insensitive fibroblasts, and the occurrence of lymphoma rather than AML sets this patient apart from typical FA. The combination of constitutional dwarfism, microcephaly, MMC-sensitive lymphocytes, and susceptibility to lymphoma represents an unusual constellation of symptoms among genetic disorders.- - - - - - - - - - ranking = 0.2keywords = breakage syndrome, breakage (Clic here for more details about this article) |
9/14. Chromosome instability and X-ray hypersensitivity in a microcephalic and growth-retarded child.We report on a microcephalic, growth-retarded newborn girl without major anomalies who has chromosome instability in lymphocytes and fibroblasts. Frequent involvement of bands 7p13, 7q34, 14q11, and 14q32 suggested the diagnosis of ataxia telangiectasia (AT) or a related disorder. Supportive evidence was radioresistant DNA synthesis in fibroblasts and radiation hypersensitivity of short-term lymphocyte cultures. Follow-up for nearly 4 years showed largely normal development, and no signs of telangiectasia, ataxia, or immunodeficiency. serum AFP levels turned from elevated at age 5 months to normal at age 2 years. We propose that our patient belongs to the expanding category of "AT-related" genetic disorders, probably to the nijmegen breakage syndrome.- - - - - - - - - - ranking = 0.2keywords = breakage syndrome, breakage (Clic here for more details about this article) |
10/14. A new chromosomal instability disorder confirmed by complementation studies.Two sisters with a complex clinical pattern, including microcephaly, microgenia, defects of skin pigmentation, anal stenosis/atresia, and combined immunodeficiency together with spontaneous chromosomal instability and cellular hypersensitivity to x-rays and bleomycin are described. Complementation studies on heterokaryons proved that the underlying genetic defect is non-allelic with that of patients with ataxia telangiectasia (complementation groups AB-E) and the nijmegen breakage syndrome, but identical with the case described by Conley et al. (1986).- - - - - - - - - - ranking = 0.2keywords = breakage syndrome, breakage (Clic here for more details about this article) |
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