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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An 8-year-old boy with an uncorrected ventricular septal defect, pulmonary stenosis, mental retardation, and gigantism died 24 hours after partial resection of a large right-sided Wilms' tumor. The presence of other abnormalities, including a small umbilical hernia and overgrowth of the external genitalia, raises the possibility that this case represents a variant of the Beckwith-Wiedemann syndrome. The typical facial features of Sotos' syndrome were not present. Gross examination of the surgical specimen revealed that tumor was present in the resected margin of left renal vein. Necropsy showed that death resulted from extensive cerebral infarction due to occlusion of the left internal carotid artery and its branches by tumor emboli. Paradoxical embolism had occurred during or soon after partial resection of the tumor mass due to passage of tumor fragments into the systemic circulation through the ventricular septal defect.
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PMID:Fatal paradoxical embolism to the left carotid artery during partial resection of Wilms' tumor. 132 57

Thirty-nine patients (82% under 1 year of age) with Wiedemann-Beckwith syndrome (WBS) were prospectively studied. To evaluate the somatometric data the normal range was set out at mean +/- 2 SD. The relevant physical findings were a characteristic face, non increased mean height and weight, normal head circumference, defective abdominal wall, a predominance of the upper segment, and tibial bowing. Mental retardation was documented in 5 cases but in only 1 it was related to hypoglycemia. The 32 cases karyotyped were normal. Since neonatal hypoglycemia is frequent (34.3% in our series) and potentially deleterious for the CNS we propose to monitor the glycemia every 6 h during the first 3 days in WBS newborns in order to correct glycemia below of 2.6 mmol/l (46.8 mg/dl) according to recent studies. The comparison with previous large series enabled us to precise the frequency, onset and evolution of the main stigmata.
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PMID:Wiedemann-Beckwith syndrome: clinical, cytogenetical and radiological observations in 39 new cases. 164 13

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.
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PMID:Familial Wiedemann-Beckwith syndrome and a second Wilms tumor locus both map to 11p15.5. 253 17

The short arm of chromosome 11 carries genes involved in malformation syndromes, including the aniridia/genitourinary abnormalities/mental retardation (WAGR) syndrome and the Beckwith-Wiedemann syndrome, both of which are associated with an increased risk of childhood malignancy. Evidence comes from constitutional chromosomal aberrations and from losses of heterozygosity, limited to tumor cells, involving regions 11p13 and 11p15. In order to map the genes involved more precisely, we have fused a mouse cell line with cell lines from patients with constitutional deletions or translocations. Characterization of somatic cell hybrids with 11p-specific DNA markers has allowed us to subdivide the short arm into 11 subregions, 7 of which belong to band 11p13. We have thus defined the smallest region of overlap for the Wilms' tumor locus bracketed by the closest proximal and distal breakpoints in two of these hybrids. The region associated with the Beckwith-Wiedemann syndrome spans the region flanked by two 11p15.5 markers, HRAS1 and HBB. These hybrids also represent useful tools for mapping new markers to this region of the human genome.
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PMID:Characterization of a panel of somatic cell hybrids for subregional mapping along 11p and within band 11p13. Subdivision of the WAGR complex region. 272 95

Wilms' tumour of the kidney usually occurs sporadically, but can also segregate as an autosomal dominant trait with incomplete penetrance. Patients with the WAGR syndrome of aniridia, genitourinary anomalies, mental retardation and high risk of Wilms' tumour have overlapping deletions of chromosome 11p13 which has suggested a possible location for a Wilms' tumour locus. Moreover, many sporadic tumours have lost a portion of chromosome 11p. A second locus at 11p15 is implicated by association of the tumour with the Wiedemann-Beckwith syndrome and by tumour-specific losses of chromosome 11 confined to 11p15. Here we report a multipoint linkage analysis of a family segregating for Wilms' tumour, using polymorphic DNA markers mapped to chromosome 11p. The results exclude the predisposing mutation from both locations. In a second family, the 11p15 alleles lost in the tumour were derived from the affected parent, thus precluding this region as the location of the inherited mutation. These findings imply an aetiological heterogeneity for Wilms' tumour and raise questions concerning the general applicability of the carcinogenesis model that has been useful in the understanding of retinoblastoma.
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PMID:Familial predisposition to Wilms' tumour does not map to the short arm of chromosome 11. 284 99

Wilms' tumour (nephroblastoma) is an embryonal neoplasm occurring in hereditary and spontaneous forms. Both types show rearrangements of the short arm of chromosome 11. The germ line of children with the rare inherited triad of aniridia, genito-urinary abnormality and mental retardation carry a chromosome 11 that has a deletion in its short arm (band 11p13) and these children are at increased risk of developing Wilms' tumour. Neonates with the Beckwith-Wiedemann syndrome, in which there may be duplication of the 11p13-11p15 region, are similarly predisposed. In the spontaneous form of the tumour a deletion of the 11p14 band in tumour cells, but not in normal cells, has been reported, and the development of homozygosity for recessive mutations in the 11p region is implicated in the aetiology of Wilms' tumour. In view of these chromosomal rearrangements and because Wilms' tumour is histologically indistinguishable from the early stages of kidney development, we have now examined the expression of genes localized to 11p in Wilms' tumour and human embryonic tissue. In 12 sporadic tumours examined, the expression of the gene coding for insulin-like growth factor-II (IGF-II), localized to the 11p15 region, was markedly increased relative to adult tissues, but was comparable to the level of expression in several fetal tissues including kidney, liver, adrenals and striated muscle. This may reflect the stage of tumour differentiation, but could also contribute to the malignant process, as IGF-II is an embryonal mitogen.
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PMID:Insulin-like growth factor-II gene expression in Wilms' tumour and embryonic tissues. 299 18

Enlarged fetal kidneys are characteristic of more than one possible diagnosis. Though infantile polycystic kidney disease is probably the most well known entity and is associated with oligohydramnios, Beckwith-Wiedemann syndrome should be considered in the differential diagnosis especially if a normal or increased amount of amniotic fluid is present. The presence of an omphalocele with a normal karyotype should also arouse suspicion. This constellation of findings carries potential morbidity including macrosomia, fetal hypoglycemia, mental retardation, microcephaly, increased risk of subsequent neoplasia, and even neonatal death. Beckwith-Wiedemann syndrome may not be obvious in the newborn period.
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PMID:Beckwith-Wiedemann syndrome: prenatal ultrasound diagnosis using standard kidney to abdominal circumference ratio. 389 53

The genetics and associated abnormalities of Wilms' tumor are reviewed. Wilms' tumor is associated with several congenital syndromes such as WAGR (Wilms' tumor, aniridia, genitourinary malformation, mental retardation) syndrome, Denys-Drash syndrome, Beckwith-Wiedemann syndrome, etc. However, the association with such syndromes is relatively infrequent and accounts for less than 5% of all clinical patients with Wilms' tumor. WAGR syndrome and Denys-Drash syndrome are associated with loss of WT1 gene located in the chromosome 11p13, and BW syndrome is considered to be due to duplication of the paternal 11p15 allele (WT2). The association of Wilms' tumor with primary brain tumors in a daughter and a mother is also described.
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PMID:[Hereditary renal tumors: Wilms' tumor--congenital anomalies' syndrome]. 853 37

The study of Wilms tumor-predisposing congenital syndromes has led to the identification of one tumor-suppressor gene, WT1, and to the localization of WT2. Molecular genetic analyses of these and sporadic Wilms tumors have clarified the role of WT1 in Wilms tumor with aniridia, genitourinary malformations, and mental retardation (WAGR)-syndrome patients, but much remains unclear in the case of WT2 and the Beckwith-Wiedemann syndrome. Loci on chromosomes 16q and 1p have now been implicated in the progression of Wilms tumor and may serve as molecular prognostic markers. It is now clear that Wilms tumors are genetically heterogeneous and may be multigenic in origin. Molecular analyses can now be used for genetic counseling in some children and may become useful in individualizing therapy.
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PMID:Molecular genetics of Wilms tumor. 859 61

Eating and sleeping problems have a high prevalence in mental retardation in general, but are also discussed as characteristic in some genetically determined disorders. A comparative analysis of eating and sleeping behaviours in 28 Prader-Willi- and 32 Williams-Beuren syndrome children by psychometric instruments confirms excessive food-seeking behaviours in PWS and selective food refusal in WBS as specific problems. In both syndromes, however, there is considerable individual variability in these symptoms.
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PMID:Specific eating and sleeping problems in Prader-Willi and Williams-Beuren syndrome. 873 69


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