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

A large body of evidence that links alterations of chromosome 11p13 to tumor formation and various developmental disorders has been accumulated. To address the underlying genetic events it would be helpful to have a comprehensive gene map of the region, and this is most readily achieved by generating the complete genomic sequence. Building upon previous mapping and YAC contig analysis we have established a 3-Mb sequence-ready PAC contig. It was constructed by chromosome walking and independently verified by fingerprint analysis of individual clones. The contig starts from the catalase gene on the centromeric side and reaches beyond the PAX6 gene at the 11p13/p14.1 boundary. Additional smaller contigs on either side were identified, but still have to be linked up. The 3-Mb contig spans the central region of deletions encompassing 16 chromosomal breakpoints in patients with WAGR syndrome (Wilms tumor, aniridia, genitourinary malformation, mental retardation), and its construction is an important step in facilitating functional analysis of these genes.
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PMID:A sequence-ready 3-Mb PAC contig covering 16 breakpoints of the Wilms tumor/anirida region of human chromosome 11p13. 979 Jul 64

In five families with questionable chromosome rearrangements, we identified an interchromosomal insertion by fluorescent in situ hybridization (FISH). In case 1 with a dir ins (5;11)(p14;q14q24) in three generations, the mentally retarded and microcephalic proband showed a 5p14-->pter deletion. In case 2, a duplication (13)(q21.31--> q31.2) combined with a deletion (11)(q14-->q22) segregated from a reciprocal ins(11;13)(q14q122)(q21.32q31.2), causing a mixed phenotype with psychomotor retardation, caput quadratum, choanal atresia, and pes equinovarus. In case 3, a dir ins (18;5)(q21.3;p13.1p14) was associated with spontaneous abortions, in case 4, the proband with mental retardation, microcephaly, and a heart defect showed a pure trisomy of (12)(q13-->q15), which had segregated from a carrier of an ins (18;12)(p11.3;q13q15). In case 5, a duplication of (10)(q26.3-->q25.2) segregated from an inv ins(5;10)(q15;q26.3q25.2), which was passed on directly from a mother to her son,with mental retardation. In all families the elucidation of the insertional translocation (IT) considerably increased the associated genetic risks of carriers. For the review, we collected data from 81 articles on 87 IT probands on ascertainment, origin, familial transmittance, progeny, and genetic risks of IT carriers. We also discussed the recombinant chromosomes and complex rearrangements associated with ITs, and listed chromosome regions occurring solely as deletions, or solely as duplications, or as both to facilitate genotype/phenotype correlations. We conclude that ITs are rare chromosomal rearrangements with an 1:80,000 incidence, of which nearly 80% were referred because of congenital abnormalities and mental retardation. A maternal origin was seen in 59.5%, a paternal origin in 26.6%, and 13.9% were de novo. No notable difference in fertility between male and female IT carriers was noticed. Bias of ascertainment was excluded in 15 familial cases and led to an estimate of the genetic risks for IT carriers of 32.0-36.0%. The mean size of the inserted regions occurring solely as duplications (n=39) measures 0.96% of the haploid autosomal length (HAL), and of regions solely occurring as deletions (n=14) 0.47% HAL. In the families where both aneusomies occurred, the size of the insertions ranged between 0.22 and 1.21% HAL. Overall, the findings fit with the general idea that a surplus of genetic material is tolerated more easily than a deficiency.
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PMID:Interchromosomal insertions. Identification of five cases and a review. 1114 Sep 39

A patient with a multiple congenital anomalies/mental retardation (MCA/MR) syndrome had an unbalanced translocation (3;5)(q26.1;p14), causing partial 5p monosomy and partial 3q trisomy. The phenotype observed in this patient results from the combination of those described in the isolated dup(3q) and del(5p) syndromes. Some clinical features of this patient are shared by the Smith-Lemli-Opitz syndrome (SLOS), a well-known MCA/MR syndrome due to the deficiency of 7-dehydrocholesterol reductase (DHCR7). We review the previously reported cases of chromosomal anomalies with clinical features suggesting SLOS.
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PMID:Unbalanced translocation (3;5)(q26.1;p14): a clinical report. 1211 9

Interstitial deletion of the proximal short arm of chromosome 4, extending from p14 to p16.1 region, results in a distinct clinical syndrome. This proximal 4p deletion syndrome is characterized by variable degrees of mental retardation, unusual facies and minor dysmorphic features. Majority of the patients also show a tall, ectomorphic habitus and normal to excessive linear growth with age. While there have been several cases of such interstitial del(4p) cases reported, familial transmission of this condition has not been documented in the literature. This is the first report of a familial transmission of proximal del(4p) from a mother to her daughter, with both patients showing similar features. This report of the familial transmission of del(4p) has wider implications in genetic counseling.
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PMID:Familial interstitial deletion of chromosome 4 (p15.2p16.1). 1465 81

A 10-year-old African-American male has been followed since 2 years of age due to his mental retardation, severe behavioral problems, and dysmorphism. Conventional cytogenetic analysis, chromosome painting, high-resolution comparative genomic hybridization (HR-CGH), and bacterial artificial chromosome fluorescent in situ hybridization (BAC FISH) revealed an apparent duplication in the short arm of a chromosome 11, dup(11)(p14.3p15.1), seen also in his mentally retarded mother. The proband had moderate to severe mental retardation, a history of IUGR, infantile hypotonia, FTT, exotropia, inguinal hernia repair, and several dysmorphic features. His mother had mild mental retardation, a history of impulsivity, assaultive outbursts, and similar dysmorphism. Although G-banding and FISH indicated a duplication, HR-CGH confined the localization of material to bands 11p14-11p15 and aided the selection of locus-specific BAC clones to more precisely characterize the duplicated region. To our knowledge, the results represent the first example of a familial, cytogenetically visible duplication of euchromatin in 11p that excludes the Beckwith-Wiedemann syndrome critical region. It is possible that one or more genes had been disrupted at the breakpoints of the above structural chromosomal rearrangement giving rise to the present phenotype.
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PMID:Duplication of 11p14.3-p15.1 in a mentally retarded proband and his mother detected by G-banding and confirmed by high-resolution CGH and BAC FISH. 1651 86

Complex chromosome rearrangements (CCRs) are rare structural abnormalities that involve at least two chromosomes and more than two breakpoints and are often associated with developmental delay, mental retardation, and congenital anomalies. We report on a de novo, apparently balanced translocation t(1;5;7)(p32.1;q14.3;p21.3) involving three chromosomes in a 7-year-old boy with severe psychomotor retardation, neonatal muscular hypertonia, congenital heart defect, polysyndactyly of hands and feet, and dysmorphic features resembling Greig cephalopolysyndactyly syndrome. Analysis of the chromosome breakpoints using fluorescence in situ hybridization (FISH) with locus-specific BAC clones and long-range PCR products did not identify chromosome imbalance at any of the interrogated regions. High-resolution comparative genomic hybridization (HR-CGH) and array CGH (aCGH) revealed two additional cryptic de novo deletions, del(1)(p31.1p31.1) and del(7)(p14.1p14.1), respectively, that are not associated with the translocation breakpoints. FISH and polymorphic marker analyses showed that the deletion on derivative chromosome 1 is between 4.2 and 6.1 Mb, and the deletion on derivative chromosome 7 is approximately 5.1 Mb, and that both are paternal in origin. The deletion on chromosome 7p encompasses the GLI3 gene that is causative for the Greig cephalopolysyndactyly, Pallister-Hall and some cases of Acrocallosal syndromes. We discuss the potential mechanisms of formation of the described CCR.
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PMID:Complex balanced translocation t(1;5;7)(p32.1;q14.3;p21.3) and two microdeletions del(1)(p31.1p31.1) and del(7)(p14.1p14.1) in a patient with features of Greig cephalopolysyndactyly and mental retardation. 1793 35

Zimmermann-Laband syndrome (ZLS) is a rare autosomal dominant inherited disorder characterized by a coarse facial appearance, gingival fibromatosis, and absence or hypoplasia of the terminal phalanges and nails of hands and feet. Additional, more variable features include hyperextensibility of joints, hepatosplenomegaly, mild hirsutism, and mental retardation. Mapping of the translocation breakpoints of t(3;8) and t(3;17) found in patients with the typical clinical features of ZLS defined a common breakpoint region of approximately 280 kb located in 3p14.3, which includes the genes CACNA2D3 and WNT5A. Breakpoint cloning revealed that both translocations most likely occurred by non-homologous (illegitimate) recombination. Mutation analysis of nine genes located in 3p21.1-p14.3, including CACNA2D3, which is directly disrupted by one breakpoint of the t(3;17), identified no pathogenic mutation in eight sporadic patients with ZLS. Southern hybridization analysis and multiplex ligation-dependent probe amplification (MLPA) did not detect submicroscopic deletion or duplication in either CACNA2D3 or WNT5A in ZLS-affected individuals. Mutation analysis of nine conserved nongenic sequence elements (CNEs) in 3p21.1-p14.3, which were identified by interspecies comparison and may represent putative regulatory elements for spatiotemporally correct expression of nearby genes, did not show any sequence alteration associated with ZLS. Taken together, the lack of a specific coding-sequence lesion in the common region, defined by two translocation breakpoints, in sporadic patients with ZLS and an apparently normal karyotype suggests that either some other type of genetic defect in this vicinity or an alteration elsewhere in the genome could be responsible for ZLS.
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PMID:Extensive molecular genetic analysis of the 3p14.3 region in patients with Zimmermann-Laband syndrome. 1793 36

A 20-month-old male patient was referred because of severe growth and mental retardation, bilateral glaucoma, hypospadias, and cryptorchidism. Karyotyping revealed a de novo complex three-chromosome rearrangement as well as deletion of band 11p13:46,XY,t(4;7;15)(q212;p14;q26),del(11) (p13p14). Trabeculectomia revealed bilateral aniridia. Surgery on the genitalia revealed male pseudohermaphroditism and bilateral gonadoblastoma. The kidneys were normal. A deficiency in catalase (CAT) activity allowed the regional assignment of the CAT gene to band 11p13.
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PMID:Aniridia, male pseudohermaphroditism, gonadoblastoma, mental retardation, and del 11p13. 2803 2

Aniridia is a congenital eye disorder with a variable degree of hypoplasia or absence of iris tissue. It is caused by loss of function of the PAX6 gene and may be an isolated ocular abnormality or part of a syndrome. WAGRO refers to a rare genetic condition leading to Wilms tumor, aniridia, genitourinary anomalies, mental retardation, and obesity and is caused by a deletion of the short arm of chromosome 11 (11p), where the PAX6 gene is located. Here, we report on an 8-year-old boy with aniridia, polar cataract, and lens subluxation along with neuropsychomotor and speech delays. Karyotype evaluation showed an interstitial deletion including region 11p13-p14, confirming the diagnosis of WAGRO syndrome. In cases of aniridia, a diagnosis of WAGRO syndrome should be considered.
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PMID:WAGRO syndrome: a rare genetic condition associated with aniridia and additional ophthalmologic abnormalities. 3111 17


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