Smith‐Magenis syndrome deletion: A case with equivocal cytogenetic findings resolved by fluorescence in situ hybridization

Juyal, Ramesh C.; Greenberg, Frank; Mengden, Gregory A.; Lupski, James R.; Trask, Barbara J.; Engh, Ger van den; Lindsay, Elizabeth A.; Christy, Heather; Chen, Ken-Shiung; Baldini, Antonio; Shaffer, Lisa G.; Patel, Pragna I.

doi:10.1002/ajmg.1320580317

Cited by 27 publications

(20 citation statements)

References 17 publications

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“…In most cases studied, the 1 7~1 1 . 2 deletion is visible on routine cytogenetic analysis; however, the molecular cytogenetic tech-nique-FISH-can be implemented to detect submicroscopic deletions (<2 megabases), verify a diagnosis of mosaicism, and detect deletions on suboptimal or low-resolution preparations [Chen et al, 1995;Juyal et al, 1995aJuyal et al, , 1995b Certainly, molecular cytogenetic analysis should be performed on any patient with a normal routine cytogenetic analysis in whom the diagnosis of SMS is strongly suspected. As clinicians become more familiar with the SMS phenotype, perhaps more individuals with submicroscopic deletions will be identified.…”

Section: Diagnosismentioning

confidence: 99%

“…The patient did have many features of SMS, however, and thus is included in this review. Two affected children with apparent chromosomal mosaicism were subsequently found to be nonmosaic by FISH analysis [Finucane et al, 1993b;Juyal et al, 1995a. By molecular analysis, the deletion in these patients is smaller than the common SMS deletion; therefore, the SMS critical region is defined by the smaller deletion Duyal et al, 1996al. Currently, there is only one SMS patient reported who appears mosaic for the 1 7~1 1 .…”

Section: Diagnosismentioning

confidence: 99%

See 1 more Smart Citation

The Smith-Magenis syndrome [del(17)p11.2]: Clinical review and molecular advances

Chen¹,

Potocki²,

Lupski

1996

Ment. Retard. Dev. Disabil. Res. Rev.

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The Smith‐Magenis syndrome (SMS) is a multiple congenital anomaly, mental retardation syndrome associated with a deletion of chromosome 17p11.2. Since the recognition of this disorder as a clinical entity in 1982, the phenotypic features of SMS have been well described. Unfortunately, the often subtle physical and chromosomal findings of SMS may preclude the diagnosis in some affected individuals. This article offers a comprehensive review of more than 100 SMS patients whose cases have been reported, including details of the more recently studied clinical aspects of SMS. SMS has been postulated to be a contiguous gene deletion syndrome. Currently, only a few genes have been mapped to the SMS critical region. Further research (including genotype‐phenotype correlation) is needed to identify the gene or genes that, when deleted, cause this disorder. Although the molecular etiology of SMS is unknown, recent investigations have identified multiple repetitive sequences within the SMS region. As described in other human disorders, repetitive sequences may be involved in homologous recombination and cause deletion. The advances in the molecular dissection of the SMS region are described, and hypotheses regarding the molecular mechanisms of SMS are offered. Parallels are made between the SMS region and other regions in the human genome where the molecular etiologies of diseases have been elucidated. © 1996 Wiley‐Liss, Inc.

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Section: Diagnosismentioning

confidence: 99%

Section: Diagnosismentioning

confidence: 99%

The Smith-Magenis syndrome [del(17)p11.2]: Clinical review and molecular advances

Chen¹,

Potocki²,

Lupski

1996

Ment. Retard. Dev. Disabil. Res. Rev.

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“…The deletions are of both maternal and paternal origin, and although data suggest there is a slight maternal origin bias, imprinting does not appear to play a role in the phenotype [38]. Some reports suggest that smaller deletions (<2 Mb) may be undetectable or ambiguously detected by standard cytogenetic methods and require the use of FISH for diagnosis [41,42], and current recommendations include FISH with an RAI1-containing probe for proper diagnosis of SMS [28].…”

Section: Genetic Diagnosis Of Smith-magenis Syndromementioning

confidence: 99%

New developments in Smith-Magenis syndrome (del 17p11.2)

Gropman

Elsea

Duncan

et al. 2007

Current Opinion in Neurology

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Findings from molecular cytogenetic analysis suggest that other genes or genetic background may play a role in altering the functional availability of RAI1 for downstream effects. Further research into additional genes in the Smith-Magenis syndrome critical region will help define the role they play in modifying features or severity of the Smith-Magenis syndrome phenotype. More research is needed to translate advances in clinical research into new treatment options to address the sleep and neurobehavioral problems in this disorder.

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“…This DOE project also supported the following additional collaborations involving similar studies: (a) identification of YACs spanning breakpoints in two incontinentia pigmentosi type I patients and discrimination between these breakpoints using cosmid subclones (Gorski et al, 1996); (c) confirmation of a deletion of PMP22 in hereditary neuropathy with liability to pressure palsy (Rao et al, 1993); (3) demonstration that a recessive form of CMTlA is caused by deletion of one allele and point mutation in the other (ibid. ); (f) positioning of YACs relative to 18q-deletions Hui et al, 1995); (g) resolution of an equivocal deletion in a Smith-Magenis syndrome patient by FISH (Juyal et al, 1995); and (h) mapping YACs and BACs relative to overlapping deletions in patients with Williams' syndrome (discussed further below; manuscript in preparation). These diverse studies were only possible because of effective reduction-to-routine practice in the range of FISH techniques.…”

Section: Organization Of Chromatinmentioning

confidence: 99%

Chromosome mapping by FISH to metaphase and interphase nuclei. Final report

Trask¹

1997

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The overall specific aims of this project were: 1) to determine the large-scale structure of interphase and metaphase chromosomes, in order to establish new capabilities for genome mapping by fluorescence in situ hybridization (FISH). to detect chromosome abnormalities associated with genetic disease and map DNA sequences relative to them in order to facilitate the identification of new genes with disease-causing mutations .to establish medium resolution physical maps of selected chromosomal regions using a combined metaphase and interphase mapping strategy and to corroborate physical and genetic maps and integrate these maps with the cytogenetic map. to analyze the polymorphism and sequence evolution of subtelomeric regions of human chromosomes. to establish a state-of-the art HSH and image processing facility in the department of Molecular Biotechnology, University of Washington, in order to map RNA sequences rapidly and accurately to benefit the Human Genome Project. 2) 4) )We achieved each of these aims during the course of this project. Details of our results are given in the following sections, which are numbered to correspond with the specific aims. Organization of chromatinThis project has contributed to new insight into the organization of human GO interphase and metaphase cells. The results defined an appropriate role for FISH in genome analysis. It was well known that DNA is tightly packaged in metaphase cells. We established that DNA sequences can only be reliably ordered along the centromere-telomere axis if they are separated by > 0.5 Mbp, while an even higher threshold may apply at the ends of chromosomes . Using a combination of interphase (untreated and borate-treated), a correlation between physical distance and genomic separation can be obtained at distances > 50 kbp.chromosome structure in part as a consequence of this DOE funding. Because chromatin is more loosely packed in interphase, resolution of DNA sequences is enhanced to -50 kbp. We made detailed measurements of the distance in interphase between probes separated by 0.05 to 200 Mbp on the same chromosome by taking advantage of mapped probe resources flowing from the human genome project. Our measurements led to a new model of chromosome organization (Sachs et al., 1995;Yokota et al., 1995b). We found that the relationship between mean-square interphase distance and genomic separation has two linear phases with a transition at -2 Mbp. On the first level, DNA appears to be randomly folded as a highly flexible polymer, but is constrained in loops several Mbp in size. This level of organization accounts for the first steep phase of the relationship, a phenomenon that can be exploited to produce detailed genomic maps. We demon-The Trask laboratory has been at the forefront of the study of the structure of interphase

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Smith‐Magenis syndrome deletion: A case with equivocal cytogenetic findings resolved by fluorescence in situ hybridization

Cited by 27 publications

References 17 publications

The Smith-Magenis syndrome [del(17)p11.2]: Clinical review and molecular advances

The Smith-Magenis syndrome [del(17)p11.2]: Clinical review and molecular advances

New developments in Smith-Magenis syndrome (del 17p11.2)

Chromosome mapping by FISH to metaphase and interphase nuclei. Final report

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