1/38. Constitutional chromosomal breakage.There were 18 individuals found to have a constitutional chromosome fragility causing an increase in break frequency. For each chromosome the breakpoint is always the same, whether it involves chromosomes from the same person, the same family, or different families. The fragile points are bands 10q24, 12q13, 16q21, 17p12, and Xq27. Autosomal constitutional fragility does not seem to have a phenotypic correspondence. They were found mostly in parents of children with chromosomal abnormalities or in couples with a history of repeated spontaneous abortions which permits one to raise the possibility of an interchromosomal effect. The six constitutional chromosomal fragilities of the x chromosome had in common the association of mental deficiency, delayed speech, and large malformed ears. The break points in constitutional chromosomal fragility were compared to those of spontaneous breaks in vitro, to those induced by x-rays, and to those in Fanconi's anemia. The theoretical consequences of these structural abnormalities are discussed as well as what to do about them when they are found.- - - - - - - - - - ranking = 1keywords = breakage (Clic here for more details about this article) |
2/38. Chromosomal abnormalities in a series of children with autistic disorder.In a series of 127 children diagnosed with autistic disorder the karyotypes of 8, on whom data were available, showed the following chromosomal abnormalities: breakage, a 47 XY pattern, trisomy 13, inversion-duplication of chromosome 15, 47 XY, der (15) (pter q15: p11 pter), 47 XXY and 46 XY, inv (2) (p11:q13pat, 3q ). Compared to those who were not karyotyped or had normal karyotypes, the children with abnormalities, although cognitively more delayed, were not rated as more severely autistic. Facial dysmorphias and minor physical anomalies tended to be more frequent in the chromosomally deviant subgroup. No differences in demographic characteristics or parental ages were evident. Results are consistent with the view of variability of expression of marker chromosome deviations and a greater severity of retardation and symptoms of autism in those affected. The relevance of the findings to a multimodal genetic etiology of autistic disorder is discussed.- - - - - - - - - - ranking = 0.25keywords = breakage (Clic here for more details about this article) |
3/38. Familial erythromelanosis follicularis and chromosomal instability.We report a 17-year-old male patient with erythromelanosis follicularis faciei et colli (EFFC), oral leucokeratosis and diabetes mellitus without islet cell antibody. His sister also had minimal findings of EFFC and minimal follicular papules on her shoulders and extensor surfaces of the arms. The father had only fine follicular papules, but no erythromelanosis. skin and mucous membrane lesions of the proband were investigated histopathologically. Interestingly, in peripheral lymphocyte cultures of the family members, chromosomal breakage was not observed spontaneously, but it was seen with nitrogen mustard, although this disease may be of autosomal recessive inheritance. Thus, we suggest that EFFC may be a polyaetiological disorder (i.e. familial and environmental) and might be considered one of the chromosomal instability syndromes.- - - - - - - - - - ranking = 0.25keywords = breakage (Clic here for more details about this article) |
4/38. 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 = 12.780445302859keywords = breakage syndrome, breakage (Clic here for more details about this article) |
5/38. 657del5 mutation in the NBS1 gene is associated with nijmegen breakage syndrome in a Turkish family.We report on a consanguineous Turkish family whose first son died of anal atresia and whose second son presented with severe pre- and post-natal growth retardation as well as striking microcephaly, immunodeficiency, congenital heart disease, chromosomal instability and rhabdomyosarcoma in the anal region. The proband was found to carry the homozygous 657del5 mutation in the NBS1 gene, which is responsible for nijmegen breakage syndrome (NBS) in most of the Slav populations. Our family, the first diagnosed with NBS in the Turkish population, represents one of the most severely affected examples of the syndrome, with profound pre- and post-natal growth retardation associated with structural abnormalities, and expands the clinical spectrum of this rare disorder.- - - - - - - - - - ranking = 12.780445302859keywords = breakage syndrome, breakage (Clic here for more details about this article) |
6/38. cavernous sinus thrombophlebitis in nijmegen breakage syndrome.The aim of the study was to present rarely reported neurologic complications in nijmegen breakage syndrome. A 13-year-old female was referred because of chronic progressive headaches. There were dysmorphic features on physical examination, which suggested a diagnosis of chromosomal instability syndrome. The results of genetic and immunologic examinations confirmed the diagnosis. Cerebral magnetic resonance imaging revealed an 8 mm thickening of the meninges over the left hemisphere, corresponding with a chronic inflammatory condition, and symptoms of left cavernous thrombophlebitis were detected. cerebrospinal fluid examination and an infusion test demonstrated disorders in its absorption. Antibiotic, anticoagulant and cerebral edema treatment was given and after 1 week improvement was observed. Regression of symptoms occurred after 14 days.- - - - - - - - - - ranking = 12.780445302859keywords = breakage syndrome, breakage (Clic here for more details about this article) |
7/38. medulloblastoma with adverse reaction to radiation therapy in nijmegen breakage syndrome.A 3-year-old child with microcephaly, facial dysmorphism, growth retardation, and developmental delay was diagnosed with medulloblastoma. craniospinal irradiation resulted in severe radiation-induced dermatitis and gastroesophagitis, unresponsive to further medical therapy. Colony survival assay on the patient's transformed lymphocytes revealed a high degree of radiosensitivity ex vivo. The presence of radiation sensitivity, both clinically and ex vivo, in association with microcephaly and growth retardation, prompted a diagnostic workup for nijmegen breakage syndrome. The patient was confirmed to have a compound heterozygote genotype for the common founder mutation of NBS1 675del5 in exon 6, and 1142delC in exon 10. Because irradiation is an important component of therapy for brain tumors, caution should be exercised in cancer patients with associated microcephaly and growth retardation, as they may turn out to have the rare diagnosis of nijmegen breakage syndrome.- - - - - - - - - - ranking = 44.336238292181keywords = nijmegen breakage syndrome, breakage syndrome, nijmegen breakage, nijmegen, breakage (Clic here for more details about this article) |
8/38. nijmegen breakage syndrome: a neuropathological study.nijmegen breakage syndrome (NBS) is an autosomal recessive disorder, due to defects in the NBS1 gene and belongs to the dna repair disorders. We report neuropathological findings of the first ever recognised case of the about 60 described cases of NBS. This patient showed severe microcephaly with a simplified gyral pattern especially in the frontal lobes. There were no signs of a degenerative disease, or of a primary migration disorder. A bulge on top of the corpus callosum, most probably a very large remnant of the involuting striae longitudinales mediales et laterales, was found. This can be considered as an incomplete development of limbic structures. The severe diminishment of neocortical neurones suggests an important role for the NBS1 gene in corticogenesis in man, as suggested earlier in animal studies of other DNA-repair genes.- - - - - - - - - - ranking = 12.780445302859keywords = breakage syndrome, breakage (Clic here for more details about this article) |
9/38. Transmission of ring chromosome 13 from a mother to daughter with both having a 46,XX, r(13)(p13q34) karyotype.ring chromosomes are thought to be the result of breakage in both arms of a chromosome, with fusion of the points of fracture and loss of the distal fragments. Another mechanism of ring formation is believed to be the simple fusion of chromosome ends with preservation of telomeric and subtelomeric sequences. Ring chromosome 13 was first described in 1968 and its incidence estimated at 1 in 58,000 live births. Severe phenotypes associated with large deletions of 13q have been described as "ring chromosome 13 syndrome." Features of the "ring chromosome 13 syndrome" include mental retardation (often severe), growth retardation, microcephaly, facial dysmorphism, and hand, foot or toe abnormalities. We report on a case of a mother and daughter with r(13) and mild phenotypes. Our patient, IA, had chromosome analysis performed at about 4(1/2) years of age due to some developmental delay. This revealed 46,XX, r(13)(p13q34) karyotype with no loss of any chromosomal band. Her mother, EA, was subsequently found to have the same ring 13. IA's maternal grandmother had a normal karyotype while her maternal grandfather was unavailable for testing. fluorescence in situ hybridization (FISH) analysis showed loss of a specific subtelomeric 13q region in r(13) in the mother. Clinically, IA had macular hyperpigmentation on the chin and mild delay in speech and fine motor skills. EA, 22 years of age, had mild short stature and borderline mental retardation. To our knowledge, this is the first report of a case of familial transmission of r(13). We compare phenotypes of our cases with those from other reported cases of r(13) and discuss the possible mechanism of formation of this ring chromosome.- - - - - - - - - - ranking = 0.25keywords = breakage (Clic here for more details about this article) |
10/38. Riyadh chromosome breakage syndrome: mental retardation with depigmentation of the skin and hair.A 20-month-old infant with "silvery-blond" hair color, widespread confettilike depigmentation of the skin, and mental retardation was found to have, in lymphocytes and fibroblast cultures, increased spontaneous chromosome breaks and breaks induced by both mitomycin and gamma-irradiation. The sister chromatid exchange frequency was normal. This child probably represents a new chromosome breakage syndrome.- - - - - - - - - - ranking = 12.780445302859keywords = breakage syndrome, breakage (Clic here for more details about this article) |
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