21/35. Constitutional interstitial deletion of 11p11 and pericentric inversion of chromosome 9 in a patient with Wiedemann-Beckwith syndrome and hepatoblastoma.A constitutional interstitial deletion on the short arm of chromosome #11 and an inversion of the heterochromatin of chromosome #9 were detected in a 1.5-year-old boy with Wiedemann-Beckwith syndrome (WBS) and hepatoblastoma. Of 37 malignant and nine benign neoplasms reported in approximately 250 cases with complete and incomplete forms of WBS, this is the fourth patient with hepatoblastoma. To date, 28 cases of WBS have been cytogenetically investigated with banding techniques. Constitutional anomalies have been found in only nine cases: Various anomalies resulting in a common triplication of the 11p15 region in six cases, reciprocal translocations t(11;22) and t(X;1) and an inversion of chromosome #2 in the three remaining cases. Triplication 11p15 was only present in one of four cases with a tumor. The breakpoints of the unique del(11)(p11.1p11.2) present in our case are proximal to those of del(11p13-11p14) and dup(11p15) observed thus far in both the aniridia-Wilms' tumor association and in WBS. Inversion of chromosome #9--one of the heterochromatin variants associated with elevated chromosomal instability, increased congenital abnormalities, and cancer proneness--may have been causally connected with a genetic imbalance resulting in the de novo deletion of 11p11. Therefore, we suggest that in these high-risk groups, C-banding studies should be performed together with high resolution chromosome analysis in order to also reveal the incidence and significance of C-band variants in individuals with such cancer prone syndromes.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
22/35. Generation of homozygosity at the c-Ha-ras-1 locus on chromosome 11p in an adrenal adenoma from an adult with Wiedemann-Beckwith syndrome.Generation of homozygosity for the human c-Ha-ras-1 locus on the short arm of chromosome #11 (11p) has been demonstrated for an adrenal adenoma from an adult with Wiedemann-Beckwith syndrome (WBS). This is the first demonstration of loss of somatic heterozygosity for a locus on 11p in an adrenal neoplasm and is the first instance where a tumor of any type, from a patient with WBS, shows loss of heterozygosity in this region of the genome. Generation of homozygosity in an adenoma, rather than a carcinoma, demonstrates that this mechanism is an early event in tumorigenesis rather than a late event associated with tumor progression.- - - - - - - - - - ranking = 0.55555555555556keywords = chromosome (Clic here for more details about this article) |
23/35. Prenatal ultrasound diagnosis of macroglossia in the Wiedemann-Beckwith syndrome.We report the ultrasound prenatal diagnosis at the 30th week of macroglossia in two sibs with the Wiedemann-Beckwith syndrome; the syndrome was also present in their mother. A study of high resolution chromosomes did not show any anomaly.- - - - - - - - - - ranking = 0.11111111111111keywords = chromosome (Clic here for more details about this article) |
24/35. The Wiedemann-Beckwith syndrome: pedigree studies on five families with evidence for autosomal dominant inheritance with variable expressivity.We describe 18 individuals from five unrelated families with various manifestations of the Wiedemann-Beckwith syndrome. pedigree analysis was performed on the 5 families and on another 19 families in the literature, each of which included more than one affected person. The following findings were obtained: 1) the clinical manifestations among the affected individuals were highly variable--those obvious in infancy tended to become less distinct with increasing age; 2) the syndrome was transmitted directly and vertically through three generations in four families, and through two generations in seven families; 3) male-to-male transmission was noted once; 4) the sex ratio in the affected individuals was not significantly different from 1; 5) the segregation ratio of the trait among the sibs of the probands was 0.571 /- 0.066; 6) the affected carrier/normal ratio was one among the offspring of the affected individuals and obligate carriers; 7) phenotrance (the expected presence of the trait in a generation) of the syndrome in the sibship of probands was complete, whereas that in earlier generations appeared low. The discrepancy is attributable to the lessening of the clinical features with increasing age as well as to a possibly less aggressive search for abnormalities in older generations. These findings indicate that the syndrome is an autosomal dominant trait with variable expressivity. High-resolution chromosome banding analysis in seven affected individuals and their respective parents showed no abnormalities.- - - - - - - - - - ranking = 0.11111111111111keywords = chromosome (Clic here for more details about this article) |
25/35. Bronze baby syndrome, biliary hypoplasia, incomplete beckwith-wiedemann syndrome and partial trisomy 11.A premature infant with duplication of material from chromosome 11 and some features of the beckwith-wiedemann syndrome developed the bronze baby syndrome when exposed to phototherapy. He subsequently developed hepatocellular dysfunction and died aged 5 weeks. Post mortem examination revealed striking hypoplasia of intralobular bile ducts but little inflammatory change or necrosis in the liver.- - - - - - - - - - ranking = 0.11111111111111keywords = chromosome (Clic here for more details about this article) |
26/35. Deletion of chromosome 11(p11p13) in a patient with beckwith-wiedemann syndrome.Four cases of duplication of a segment of 11p have been reported in patients with beckwith-wiedemann syndrome (Waziri et al. 1983, Turleau et al. 1984). We describe a patient with beckwith-wiedemann syndrome who has a deletion of chromosome 11(p11p13) and suggest involvement of this chromosomal region in both the duplicated and deleted states such as occurs in prader-willi syndrome.- - - - - - - - - - ranking = 0.55555555555556keywords = chromosome (Clic here for more details about this article) |
27/35. Abnormality of chromosome 11 in patients with features of beckwith-wiedemann syndrome.Two unrelated children with features of beckwith-wiedemann syndrome have been found to have partial duplication of chromosome 11p. A review of six other reported cases of partial duplication of 11 p revealed features of this syndrome not previously recognized. We suggest that karyotype studies with banding techniques should be done in children with features of beckwith-wiedemann syndrome and developmental delay or retardation.- - - - - - - - - - ranking = 0.55555555555556keywords = chromosome (Clic here for more details about this article) |
28/35. Non-random x chromosome inactivation in an affected twin in a monozygotic twin pair discordant for Wiedemann-Beckwith syndrome.Wiedemann-Beckwith syndrome (WBS) is a syndrome including exomphalos, macroglossia, and generalized overgrowth. The locus has been assigned to 11p15.5, and genomic imprinting may play a part in the expression of one or more genes involved. Most cases are sporadic. An excess of female monozygotic twins discordant for WBS have been reported, and it has been proposed that this excess could be related to the process of x chromosome inactivation. We have therefore studied x chromosome inactivation in 13-year-old monozygotic twin girls who were discordant for WBS. In addition, both twins had tourette syndrome. The twins were monochorionic and therefore the result of a late twinning process. This has also been the case in previously reported discordant twin pairs with information on placentation. x chromosome inactivation was determined in dna from peripheral blood cells by PCR analysis at the androgen receptor locus. The affected twin had a completely skewed X inactivation, where the paternal allele was on the active X chromosome in all cells. The unaffected twin had a moderately skewed X inactivation in the same direction, whereas the mother had a random pattern. Further studies are necessary to establish a possible association between the expression of WBS and x chromosome inactivation.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
29/35. genome-wide loss of maternal alleles in a nephrogenic rest and Wilms' tumour from a BWS patient.A patient with beckwith-wiedemann syndrome (BWS) presented with Wilms' tumour. Examination of the nephrectomy specimen showed, in addition to the tumour, the presence of nephrogenic rests. Nephrogenic rests are thought to be precursor lesions from which a Wilms' tumour may develop. A molecular analysis examining the loss of constitutional heterozygosity (LOCH), initially for chromosome 11, was performed on peripheral blood, the normal kidney, nephrogenic rest and tumour material. The study was extended to include markers from all 23 chromosomes. At each informative, locus, LOCH of the maternal allele was shown in the nephrogenic rest and tumour material. In addition, the normal kidney displayed allele imbalance. It would appear from these results that either extensive LOCH across the genome was an early genetic event in the development of malignancy in this patient or that the tumour and rest developed from cells containing no maternal chromosomes. The apparent LOCH seen in the normal kidney sample implies that full reduction to homozygosity is consistent with a histologically normal appearance. Putative mechanisms to explain this phenomenon are discussed.- - - - - - - - - - ranking = 0.33333333333333keywords = chromosome (Clic here for more details about this article) |
30/35. Sex dependent transmission of beckwith-wiedemann syndrome associated with a reciprocal translocation t(9;11)(p11.2;p15.5).beckwith-wiedemann syndrome (BWS), a disorder associated with neonatal hypoglycaemia, increased growth potential, and predisposition to Wilms's tumour (WT) and other malignancies, has been mapped to 11p15. The association with 11p15 duplications of paternal origin, of balanced translocations and inversions with breakpoints within 11p15.4-p15.5 of maternal origin, and the demonstration of uniparental paternal 11p15 isodisomy in some sporadic cases point towards the involvement of genomic imprinting. In agreement with this, we show the paternal origin of a de novo 9;11 translocation in a phenotypically normal mother, whose carrier daughter developed BWS. This supports the fact that BWS associated with balanced chromosome mutations is transmitted in the same sex dependent pattern as non-cytogenetic forms of familial BWS.- - - - - - - - - - ranking = 0.11111111111111keywords = chromosome (Clic here for more details about this article) |
| <- Previous || Next -> |