首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Wilms tumor of the kidney occurs with increased frequency in association with two clinically and cytogenetically distinct congenital syndromes, the Wiedemann-Beckwith syndrome (WBS) and the triad of aniridia, genitourinary anomalies, and mental retardation (WAGR). Constitutional deletions in the latter situation and similar alterations in sporadic Wilms tumors have implicated the chromosomal 11p13 region in neoplastic development. In contrast, some sporadic cases of WBS have been reported to have a constitutional duplication of chromosome 11p15. In order to resolve this seeming paradox, we have analyzed a family segregating WBS for linkage to DNA markers mapped to chromosome 11p. Consonant with the cytogenetic alterations in sporadic WBS cases, we obtained evidence for tight linkage of the mutation causing the syndrome to markers located at 11p15.5. Also consistent with this localization, we identified a subset of Wilms tumors, not associated with WBS, which have attained somatic homozygosity through mitotic recombination, with the smallest shared region of overlap being distal to the beta-globin complex at 11p15.5. These data provide evidence that familial WBS likely results from a defect at the same genetic locus as does its sporadic counterpart. Further, the data suggest there is another locus, distinct from that involved in the WAGR syndrome, which plays a role in the association of Wilms tumor with WBS.  相似文献   

2.
Williams-Beuren syndrome (WBS), caused by a heterozygous deletion at 7q11.23, represents a model for studying hypertension, the leading risk factor for mortality worldwide, in a genetically determined disorder. Haploinsufficiency at the elastin gene is known to lead to the vascular stenoses in WBS and is also thought to predispose to hypertension, present in approximately 50% of patients. Detailed clinical and molecular characterization of 96 patients with WBS was performed to explore clinical-molecular correlations. Deletion breakpoints were precisely defined and were found to result in variability at two genes, NCF1 and GTF2IRD2. Hypertension was significantly less prevalent in patients with WBS who had the deletion that included NCF1 (P=.02), a gene coding for the p47(phox) subunit of the NADPH oxidase. Decreased p47(phox) protein levels, decreased superoxide anion production, and lower protein nitrotyrosination were all observed in cell lines from patients hemizygous at NCF1. Our results indicate that the loss of a functional copy of NCF1 protects a proportion of patients with WBS against hypertension, likely through a lifelong reduced angiotensin II-mediated oxidative stress. Therefore, antioxidant therapy that reduces NADPH oxidase activity might have a potential benefit in identifiable patients with WBS in whom serious complications related to hypertension have been reported, as well as in forms of essential hypertension mediated by a similar pathogenic mechanism.  相似文献   

3.
Here, we report and investigate the genomic alterations of two novel cases of Non-Hodgkin Lymphoma (NHL) in children with Williams-Beuren syndrome (WBS), a multisystem disorder caused by 7q11.23 hemizygous deletion. Additionally, we report the case of a child with NHL and a somatic 7q11.23 deletion. Although the WBS critical region has not yet been identified as a susceptibility locus in NHL, it harbors a number of genes involved in DNA repair. The high proportion of pediatric NHL reported in WBS is intriguing. Therefore, the role of haploinsufficiency of genes located at 7q11.23 in lymphomagenesis deserves to be investigated.  相似文献   

4.
Summary A patient with pure trisomy of the short arm of chromosome 17 in 60% of the examined cells is reported. She presented a variant chromosome 1 with partial pericentric inversion and increased centromeric heterochromatin in one chromosome 17. The cytogenetic findings are discussed. The clinical findings are compared to those found in other reported cases of partial trisomy 17 and a delineation of a pure trisomy 17p attempted.  相似文献   

5.
This study examined the relationship between dominance rank and several physiological and behavioral measures in stable, captive, all-male squirrel monkey groups. Four groups, each containing three males, were observed for 12 weeks during the breeding season. Relative dominance ranking among males in each group was based on the direction of agonistic behaviors displayed. For each subject, whole blood serotonin (WBS), plasma testosterone (T), and cortisol (C) were sampled 4 to 6 times over the course of the study. Samples were separated by 1- to 2-week intervals. Each group had a stable linear dominance hierarchy. WBS had small intraanimal variance and was positively related to dominance rank. In contrast, T and C were highly variable within subjects and were unrelated to dominance rank. Among alpha males, concentrations of T and C were positively correlated, and WBS and C were negatively correlated. The effect of dominance rank on the relationship between within-animal fluctuations in WBS, T, and C and behavior was also assessed. In dominant, but not subordinate subjects, intraanimal fluctuations in WBS correlated with agonistic behavior initiated, and fluctuations in C and T correlated with huddling. In beta and gamma males, C was related to agonism received, and in gamma males to food stealing received. Dominance status also affected endocrine response to the stress of capture but not the rate of sneezing. Sneezing was positively correlated with T concentrations irrespective of dominance rank. These results extend the association between WBS and dominance rank previously reported in Old World monkeys to a New World monkey species, support previous suggestions that mean T and C titers are not reflective of dominance rank in well-established groups, and indicate that dominance rank affects adrenocortical response to the stress associated with capture and anesthesia.  相似文献   

6.
Each species is uniquely influenced by anthropogenic climate change. Change in temperature and precipitation due to climate change may lead to species adaptation or extinction, or in some cases, a range shift. To know the influence of climate change on a restricted and endemic bird species of the Western Ghats (WG), White-bellied Sholakili (WBS) Sholicola albiventris (Blanford, 1868), we conducted a study by using species distribution modelling. We considered 73 spatial bias-corrected occurrence points of WBS along with environmental variables like the mean temperature of coldest quarter (Bio 11), precipitation of driest month (Bio 14) and mean precipitation of warmest quarter (Bio 18). We used the MaxEnt application with ENM evaluate tool in R statistical package for developing a climate model for WBS. Bio 11 was observed to be the most crucial climate variable shaping the habitat of WBS. The current study predicts that only 2823km2 in WG is suitable for WBS. One-third of this area falls under the protected area network, of which 52% is becoming unsuitable to this narrow endemic due to climate warming. The model also predicts 26% to 45% habitat loss under different climate change scenarios by the 2050s.  相似文献   

7.
8.
Three related new cases with almost complete trisomy 11p due to paternal balanced translocation 46, XY, t(7; 11) (q36.1; p11.1) are reported. The proband (Case 1) was a malformed stillborn with exomphalos, case 2 was diagnosed in the first trimester by direct chromosome preparations from chorionic villi, and confirmed on fetal products after termination of pregnancy. Case 3, a cousin to cases 1 and 2, was a 29-weeks-old fetus with omphalocele discovered at ultrasound. Literature reports of trisomy 11p are reviewed with regard to those new cases, and the possible relationship of this chromosome imbalance with the Beckwith-Wiedemann Syndrome is discussed.  相似文献   

9.
A clinical and cytogenetic investigation carried out in a special institution for mentally retarded patients revealed 82 cases of oligophrenia, amongst whom were found 56 normal karyotypes (68.3%). Out of 25 karyotypes with chromosome anomalies or variants there were 18 cases of trisomy 21 and 7 others: one case of mosaicism with balanced translocation, 46,XX/46,XX,6p+,17q-; one case of partial trisomy, 46,XX,11q+; one case of pericentric inversion, 46,XY,inv(1) (p13,q21); one case with 8% chromosome breaks; three cases of marker chromosomes, of which one was of karyotype 46,XX,1qh+, and two (oligophrenic sisters) 46,XX,21p+. Moreover, there was an interesting case of testicular feminisation in a 9-year-old girl with karyotype 46,XY. The authors' results corroborate those obtained in several important previous studies based on much larger numbers of patients. Amongst the 56 cases where the karyotype was shown to be normal, there were 15 for whom a probably exogenic cause of the oligophrenia could be established, occurring mainly during the perinatal period. The authors were also able to confirm that the genetic factor plays an important role in the incidence of mental retardation, since in 22 examined patients, i.e. 26.8% of all cases, the condition was of familial type. Some interesting observations of idiopathic oligophrenia are reported, as well as several cases with well-known syndromes (Crouzon's and Cornelia de Lange's syndromes, hypothyroidism). Two cases of incest between father and daughter, which had produced children with serious oligophrenia associated, in one case, with deaf-mutism, microphthalmia, microcephaly and sclerocornea, are also discussed. The data show that mental retardation can frequently have a genetic cause, either of mendelian, chromosomal or multifactorial origin.  相似文献   

10.
Wilms tumor, a common childhood renal tumor, occurs in both a heritable and a nonheritable form. The heritable form may occasionally be attributed to a chromosome deletion at 11p13, and tumors from patients with normal constitutional chromosomes often show deletion or rearrangement of 11p13. It has been suggested that a germinal or somatic mutation may occur on one chromosome 11 and predispose to Wilms tumor and that a subsequent somatic genetic event on the normal homologue at 11p13 may permit tumor development. To study the frequency and mechanism of such tumor-specific genetic events, we have examined the karyotype and chromosome 11 genotype of normal and tumor tissues from 13 childhood renal tumor patients with different histologic tumor types and associated clinical conditions. Tumors of eight of the 12 Wilms tumor patients, including all viable tumors examined directly, show molecular evidence of loss of 11p DNA sequences by somatic recombination (four cases), chromosome loss (two cases), and recombination (two cases) or chromosome loss and duplication. One malignant rhabdoid tumor in a patient heterozygous for multiple 11p markers did not show any tumor-specific 11p alteration. These findings confirm the critical role of 11p sequences in Wilms tumor development and reveal that mitotic recombination may be the most frequent mechanism by which tumors develop.  相似文献   

11.
Renewed examinatinon with improved banding techniques of a boy previously reported to have the karyotype 46, XY,del(12)(p11) revealed a translocation 46, XY,t(10;12)(p13;p11), and reexamination of a boy previously reported to have the karyotype 46,XY/46,XY,del(5)(p13) showed the same mosaicism, but with a significantly lower frequency of cells with del(5)(p13), 8% compared with 23% at the time of birth. The decrease of the frequency of cells with chromosome abnormality in mixoploids during the first years of life as found in the present case as well as in prevously reported cases is discussed.  相似文献   

12.
Summary A woman with a balanced translocation t(3;11)(p27;q23) has had three abnormal children. The first child died in infancy, and of the two survivors who show segregation of the derivative maternal translocated chromosomes, one exhibits partial trisomy 11q and the other partial monosomy 11q. The two cases are compared with each other and with reported examples. Moreover, 11q break points are discussed.  相似文献   

13.
Williams-Beuren syndrome (WBS) is a genetic disease characterized by distinct facial features,short stature,hypotonia,mental retardation,overfriendly and hyper-social behavior,congenital heart disease,infantile hypercalcemia,arterial hypertension and other variable clinical manifestations in organs and systems such as the kidneys,eyes,gastrointestinal and osteoarticular systems (Morris and Mervis,2000).This mental retardation syndrome occurs in 1/20,000 live births (Meyer-Lindenberg et al.,2006).It is caused by a 1.55-1.84 Mb microdeletion in 7q 11.23,a region containing approximately 28genes.Depending on the genes deleted,the phenotypes of WBS patients range from isolated supravalvular aortic stenosis (SVAS) to full expression of the WBS characteristics.Most cases are sporadic (Ewart et al.,1993;Perez Jurado et al.,1996).  相似文献   

14.
To discuss the autologous serum production for cartilage tissue engineering, we compared three kinds of sera: whole blood-derived serum (WBS), platelet-containing plasma-derived serum (PCS), and plasma-derived serum (PDS), on the growth factor contents and their biological effects on human auricular chondrocytes. EGF, VEGF and PDGF levels were highest in WBS, while PCS and PDS followed WBS. The proliferation effects of WBS were the most pronounced, followed by that of PCS, both of which realized a 1000-fold-increase in chondrocyte numbers at the third passage, whereas PDS reached it after passage 4. No significant differences were observed in histology or cartilaginous matrix measurements of tissue-engineered cartilage produced from chondrocytes cultured under different serum conditions. WBS would be clinically useful because of its potent proliferation effects, while PCS, which possibly saves the red cell concentrate, may be an option in cases where there are elevated risks of blood loss.  相似文献   

15.
Summary Two cases of trisomy 12p due to a familial translocation t(12;21) (p11;p11) inherited through three generations are presented. The clinical features of both affected individuals are consistent with those previously reported. Study of the NORs by silver staining showed translocation of the NOR from chromosome 21 onto the der(12) and suggested that the activity of this site has been suppressed in some carriers.  相似文献   

16.
Summary A family is reported in which the mother and two sons are carriers of a Y-to-X translocation, der(X)t(X;Y) (p22;q11). All of the three carriers have short statute and disproportion of extremities, but otherwise normal phenotype. One of the sons, the propositus, has been affected with schizophrenia. Evidence was obtained that male carriers are probable sterile; both sons aged 26 and 30 years had azoospermia and the biopsied specimens of the testis had histologic pictures showing spermatogenetic arrest. The mother was H-Y weakly positive, and the normal X chromosome was inactivated in the majority of the cells analyzed. Dermatoglyphics of the three carriers were unusual and dissimilar to the features of Turner's syndrome. The clinical and cytogenetic findings in the present study are compared with those of the previously reported familial cases, and the genetic background causing phenotypic abnormalities in the male and female carriers is discussed.  相似文献   

17.
A female infant with severe growth-weight retardation and with a ring chromosome 11, associated with trisomy X in 15% of metaphases, has been reported. A literature review of cases of r(11) shows that the clinical features of these patients, although showing different frequencies, are similar to those of the del(11q) syndrome. It has been suggested that the variability of the mental retardation in r(11) patients is attributable to the unstability of the ring and to the different break points in these two chromosomal rearrangements. The origin of the r(11) was also addressed by studying fragile sites of the parents at 11p15 and 11q25.  相似文献   

18.
A few cases of Beckwith-Wiedemann syndrome (BWS) have in common a duplication of 11p15. Among the genes located in 11p15, c-Ha-ras 1 (HRAS1), insulin (INS), and insulin-like growth factor II (IGF2) may account for the clinical features and the increased risk for malignancy. Using eight 11p15 markers including HRAS1, INS and IGF2 we have studied eight sporadic and hereditary cases of BWS whether or not associated with a nephroblastoma. By gene dosage determination and family studies, we have shown the following: the eight patients examined had an apparent diploid representation of all of the eight markers studied, thus indicating that a microduplication of these markers or of the region characterized by these markers is not a common event in BWS; in a family with three affected sibs the genes for HRAS1 and INS/IGF2 did not cosegregate with BWS and therefore may not participate in the pathogenic processes here observed.  相似文献   

19.
Whole blood serotonin (WBS) determinations were made in 56 pigtailed macaques (Macaca nemestrina) with approximately equal numbers in three age groups: young-adult (4–5 years), middle-aged (13–14 years), and old (over 18 years). The animals were housed in ten living groups with one female and male of each age group in each living group. Half of the groups were fed a diet high in lipid, cholesterol, simple sugars, and sodium; the other half received a restricted diet. Three determinations per animal showed WBS levels to be stable at two times of day and at a 1-week interval, and individual differences were stable over several months' time. The mean WBS concentrations in M. nemestrina were found to be considerably higher than those reported for other species. The mean levels in females were almost 25% higher than in males. No significant effects of age, diet, or dominance status were detected.  相似文献   

20.
Summary Two patients with trisomy 11p15 and features of Beckwith-Wiedemann syndrome are reported. The first is a female infant with gigantism, macroglossia, abdominal hypotonia with umbilical hernia, moderate mental retardation, malformative uropathy, and atrial septal defect. Trisomy 11p15 was due to de novo duplication. The second patient was a stillborn (32–33 weeks pregnancy) with an abnormal tongue, posterior diaphragmatic eventration, inner organ congestion mainly of the adrenals. Trisomy 11p15 was due to a t(4;11)(q33;p14)pat. The association of trisomy 11p15 and Beckwith-Wiedemann syndrome is discussed with regard to cytogenetic data and the gene content of 11p, notably the genes coding for insulin and predisposition to Wilms tumour.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号