1/110. Chromosome instability in lymphocytes from two patients affected by three sequential primary cancers: the role of fragile sites.The chromosomal aberration rate and the expression of fragile sites induced by aphidicolin were evaluated in metaphase chromosomes obtained from peripheral blood lymphocytes of two untreated patients with multiple primary cancers. Spontaneous aberrations of chromosome number and structure and chromosome fragility were compared with controls with the use of the same methods. Chromosomal aberration rates and expression frequencies of fragile sites were significantly higher in the patients than in normal control subjects. In the patients, all but one structural chromosome aberration involved at least one fragile site. Our results suggest that fragile sites may be unstable regions of the human genome, which might play an important role in the genetic instability associated with cancer predisposition.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/110. Interstitial deletion of the long arm of chromosome 2: a clinically recognizable microdeletion syndrome?We report on a boy with an interstitial deletion of the long arm of chromosome 2 with breakpoints in chromosome bands q23 and q24.3. Main features were low-set and malformed ears, digital anomalies and congenital heart defects, which have also been reported in most of the previously described cases. A comparison of the features of the present patient with those in previously reported cases suggests the deletion 2q23q24 to be a clinically recognizable syndrome.- - - - - - - - - - ranking = 1.5keywords = chromosome (Clic here for more details about this article) |
3/110. Three probands with autistic disorder and isodicentric chromosome 15.We have identified three unrelated probands with autistic disorder (AD) and isodicentric chromosomes that encompass the proximal region of 15q11.2. All three probands met the diagnostic and statistical manual of mental disorders, fourth edition [DSM-IV; American Psychiatric association, 1994], and international classification of diseases ( ICD-10) diagnostic criteria for AD, confirmed with the Autism Diagnostic interview -Revised (ADI-R). Chromosome analysis revealed the following karyotypes: 47,XX, idic(15)(q11.2), 47,XX, idic(15) (q11.2), and 47,XY, idic(15)(q11.2). Haplotype analysis of genotypic maker data in the probands and their parents showed that marker chromosomes in all three instances were of maternal origin. Comparison of the clinical findings of the three AD probands with case reports in the published literature (N = 20) reveals a clustering of physical and developmental features. Specifically, these three probands and the majority of reported probands in the literature exhibited hypotonia (n = 13), seizures (n = 13), and delayed gross motor development (n = 13). In addition, clustering of the following clinical signs was seen with respect to exhibited speech delay (n = 13), lack of social reciprocity (n = 11), and stereotyped behaviors (n = 12). Collectively, these data provide further evidence for the involvement of chromosome 15 in AD as well as present preliminary data suggesting a clustering of clinical features in AD probands with proximal 15q anomalies.- - - - - - - - - - ranking = 1.75keywords = chromosome (Clic here for more details about this article) |
4/110. Molecular and clinical characterization of a patient with a chromosome 4p deletion, wolf-hirschhorn syndrome, and congenital glaucoma.wolf-hirschhorn syndrome is a developmental disorder associated with hemizygous deletion of the distal short arm of chromosome 4. We have identified a patient affected with wolf-hirschhorn syndrome and early onset glaucoma. Five other patients with wolf-hirschhorn syndrome and early onset glaucoma or ocular anomalies associated with early onset glaucoma have been previously described, suggesting that the association with wolf-hirschhorn syndrome is not coincidental. The infrequent association of early onset glaucoma suggests that the chromosomal region commonly deleted in Wolf-Hirschhorn patients does not contain genes responsible for early onset glaucoma. In this study, we performed a molecular characterization of the deleted chromosome 4 to determine the extent of the deletion in an attempt to begin to identify the chromosomal region responsible for the associated glaucoma. Using microsatellite repeat markers located on 4p, we determined that the deletion spanned a 60-cM region including the minimal Wolf-Hirschhorn region. The proximal breakpoint occurred between markers D4S3045 and D4S2974. These results support the hypothesis that patients with wolf-hirschhorn syndrome and early onset glaucoma may have large deletions of 4p that include a gene(s) that may be responsible for a dominant form of congenital glaucoma.- - - - - - - - - - ranking = 1.5keywords = chromosome (Clic here for more details about this article) |
5/110. Rearrangement in the coding region of the MYCN gene in a subset of amplicons in a case of neuroblastoma with MYCN amplification.The MYCN gene is often amplified but rarely rearranged in neuroblastoma. We report, for the first time, a rearrangement within the MYCN coding region in a metastatic neuroblastoma in a 3-year-old boy with MYCN amplification in his primary tumor. The rearrangement occurred 46 nucleotides downstream from the ATG codon in exon 2 of MYCN. The amplification level of the rearranged copies of the MYCN gene was lower than that of the unrearranged copies of MYCN. These results indicate that the rearrangement occurred after initial MYCN gene amplification. Monochromosomal somatic cell hybrid mapping of the novel region fused to exon 2 of MYCN localized it to chromosome 2, suggesting that this rearrangement resulted from an interstitial deletion, presumably within the MYCN amplicon itself.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
6/110. Acral myxoinflammatory fibroblastic sarcoma with unique clonal chromosomal changes.Acral myxoinflammatory fibroblastic sarcoma is a rare tumor of the distal extremities. We present the hitherto unreported karyotypic abnormalities of this new entity. The tumor presented as a mass in the dorsum of the foot in a 53-year-old woman and showed the typical virocyte-like and lipoblast-like cells in a myxoid and inflammatory background. cytogenetic analysis revealed a complex karyotype with a reciprocal translocation t(1;10) (p22;q24) in addition to the loss of chromosomes 3 and 13. fluorescence in situ hybridization with the 769E11YAC and BAC 31L5 and 2H23 probes showed the breakpoint to be located proximally to BCL10 and distally to GOT1 genes on chromosomes 1p22 and 10q24, respectively. The presence of these clonal chromosomal changes supports the neoplastic nature of acral myxoinflammatory fibroblastic sarcoma and underscores that it represents a separate entity.- - - - - - - - - - ranking = 0.5keywords = chromosome (Clic here for more details about this article) |
7/110. association of the congenital bone marrow failure syndromes with retinopathy, intracerebral calcification and progressive neurological impairment.We present a child with Fanconi anaemia and congenital hypopituitarism, who developed intracerebral calcifications, progressive spasticity and retinopathy. The chromosome fragility with mitomycin C was increased in both the patient and his sibling, confirming a diagnosis of Fanconi anaemia. Aplastic anaemia in association with intracerebral calcifications has been described in patients with dyskeratosis congenita and Revesz syndrome, but not so far in confirmed cases of Fanconi anaemia. This case further illustrates the greater overlap of associated features in congenital bone marrow failure syndromes. It also indicates that Fanconi anaemia should be actively excluded where such associated features are found.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
8/110. Dominant inheritance of cleft palate, microstomia and micrognathia--possible linkage to the fragile site at 16q22 (FRA16B).We report a family in which a father and his three children are affected with microstomia, micrognathia and partial or complete cleft of the hard and soft palate. The probands were non-identical twins, a boy and a girl, both noted to have the above features soon after birth. Their father was diagnosed with a submucous cleft of the palate at the age of 4 years and their older brother has milder facial features and a bifid uvula. All affected family members were demonstrated to have a fragile site on chromosome 16q22 but otherwise normal karyotypes. Of interest is a previously described family with autosomal dominant inheritance of U-shaped cleft palate, microstomia, micrognathia and oligodontia where all affected members were shown to have the fragile site at 16q22 in a proportion of their cells [Bettex et al. (1998) Eur J Pediatr Surg 8:4-8]. We propose that these two conditions are the same and represent a distinctive syndrome involving aberrant orofacial development that may be linked to the fragile site at 16q22.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
9/110. Clinical, cytogenetic and molecular investigations in three patients with wolf-hirschhorn syndrome.Clinical, cytogenetic and molecular studies were performed in three patients with wolf-hirschhorn syndrome (WHS). In all cases the altered chromosome 4 appeared to be the result of a de novo deletion. Cytogenetic investigations located the breakpoint at 4p15.3 and 4p13. With cytogenetic methods it was not possible to decide whether these deletions were terminal or interstitial. dna methods also failed to define a distal breakpoint within the 4p16.3 region which might have indicated an interstitial deletion. According to the literature, the paternal chromosome 4 is preferentially deleted in most patients with WHS. dna analysis with polymorphic markers out of the 4p16.3 region revealed that in two of the cases reported here the deleted segment was of paternal and in one case of maternal origin.- - - - - - - - - - ranking = 0.5keywords = chromosome (Clic here for more details about this article) |
10/110. 6p23 deletion mosaicism in a woman with recurrent abortions and idiopathic hypoprolactinemia.A woman with a history of recurrent abortions, idiopathic hypoprolactinemia, and an apparent 6p partial deletion mosaicism is described. The breakpoint in the short arm of chromosome 6 was in the p23 region. This deletion could have been caused by a fragile site in 6p23.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
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