Familial partial trisomy 8p without dysmorphic features and only mild mental retardation

Engelen, J. J. M.; Die-Smulders, C.E.M. de; Sijstermans, J. M. J.; Meers, L E C; Albrechts, J. C. M.; Hamers, A.J.H.

doi:10.1136/jmg.32.10.792

Cited by 32 publications

(33 citation statements)

References 20 publications

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“…Based on the comparison of clinical phenotypes of patients with trisomy of 8p23→q10 due to sSMCs(8) (Demori et al 2004) or with tri-and tetrasomy of region 8p21→q11 (Liehr et al 2006), we propose that corpus callosum, lower lip, and developmental delay result from the presence of these sSMCs. The psychomotor retardation, facial anomalies, and brachycephaly present in patient NP, are clinical symptoms that can be found in patients with partial trisomy of 8p (Engelen et al 1995). The other sSMC in patient NP derives from chromosome 21.…”

Section: Discussionmentioning

confidence: 99%

Molecular cytogenetic characterization of eight small supernumerary marker chromosomes originating from chromosomes 2, 4, 8,18, and 21 in three patients

Pietrzak¹,

Mrasek

Obersztyn³

et al. 2007

J Appl Genet

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Small supernumerary marker chromosomes (sSMCs) are a morphologically heterogeneous group of additional structurally abnormal chromosomes that cannot be identified unambiguously by conventional banding techniques alone. Molecular cytogenetic methods enable detailed characterization of sSMCs; however, in many cases interpretation of their clinical significance is problematic. The aim of our study was to characterize precisely sSMCs identified in three patients with dysmorphic features, psychomotor retardation and multiple congenital anomalies. We also attempted to correlate the patients' genotypes with phenotypes by inclusion of data from the literature. The sSMCs were initially detected by G-banding analysis in peripheral blood lymphocytes in these patients and were subsequently characterized using multicolor fluorescence in situ hybridization (M-FISH), (sub)centromere-specific multicolor FISH (cenM-FISH, subcenM-FISH), and multicolor banding (MCB) techniques. Additionally, the sSMCs in two patients were also studied by hybridization to whole-genome bacterial artificial chromosome (BAC) arrays (array-CGH) to map the breakpoints on a single BAC clone level. In all three patients, the chromosome origin, structure, and euchromatin content of the sSMCs were determined. In patient RS, only a neocentric r(2)(q35q36) was identified. It is a second neocentric sSMC(2) in the literature and the first marker chromosome derived from the terminal part of 2q. In the other two patients, two sSMCs were found, as M-FISH detected additional sSMCs that could not be characterized in G-banding analysis. In patient MK, each of four cell lines contained der(4)(:p11.1-->q12:) accompanied by a sSMC(18): r(18)(:p11.2-->q11.1::p11.2-->q11.1:), inv dup(18)(:p11.1-->q11.1::q11.1-->p11.1:), or der(18) (:p11.2-->q11.1::q11.1-->p11.1:). In patient NP, with clinical features of trisomy 8p, three sSMCs were characterized: r(8)(:p12-->q11.1::q11.1-->p21:) der(8) (:p11.22-->q11.1::q11.1-->p21::p21-->p11.22:) and der(21)(:p11.1-->q21.3:). The BAC array results confirmed the molecular cytogenetic results and refined the breakpoints to the single BAC clone resolution. However, the complex mosaic structure of the marker chromosomes derived from chromosomes 8 and 18 could only be identified by molecular cytogenetic methods. This study confirms the usefulness of multicolor FISH combined with whole-genome arrays for comprehensive analyses of marker chromosomes.

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Section: Discussionmentioning

confidence: 99%

Molecular cytogenetic characterization of eight small supernumerary marker chromosomes originating from chromosomes 2, 4, 8,18, and 21 in three patients

Pietrzak¹,

Mrasek

Obersztyn³

et al. 2007

J Appl Genet

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“…Further FISH analysis might identify EVs as well as genuine duplications among these reported cases. Secondly, larger duplications of 8p21.3 -p23.1 have been associated with developmental or speech delay 13,14 and, in the proband of family 1 of Fan et al, 13 a complex heart defect. However, the mother and a sibling with the same duplication had no heart defects.…”

Section: Discussionmentioning

confidence: 99%

Duplications and copy number variants of 8p23.1 are cytogenetically indistinguishable but distinct at the molecular level

et al. 2005

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“…28 Fluorescence in situ hybridization A cytogenetic cell suspension (methanol/acetic acid fixed cells kept at À201C) was available from 13 cases for molecular cytogenetic investigation. FISH was performed according to established protocols (Engelen et al 29 (cases 1, 2, 8, 18-20)) or according to Dierlamm et al 30 (cases 9-17, 21). Whole chromosome painting probes (Cambio, Cambridge, UK) were applied to confirm the presence of a t(2;3).…”

Section: Cytogeneticsmentioning

confidence: 99%

Translocation t(2;3)(p15–23;q26–27) in myeloid malignancies: report of 21 new cases, clinical, cytogenetic and molecular genetic features

et al. 2004

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Chromosomal rearrangements involving 3q26 either due to inversion or translocation with various partner chromosomes are a recurrent finding in malignant myeloid disorders. Typically, these chromosome aberrations contribute to ectopic expression of or to the formation of fusion genes involving the EVI1 proto-oncogene. Chromosomal translocations involving the short arm of chromosome 2 (p15-p23) and the distal part of the long arm of chromosome 3 (q26-q27) are a rare but recurrent finding in patients with myeloid malignancies, and are assumed to be part of this spectrum of disorders. Thus far, however, these translocations have been poorly studied. Here, we present 21 new cases with myelodysplasia, acute myeloid leukemia or CML in blast crisis, which upon karyotyping showed the presence of a t(2;3). Furthermore, an extensive literature review disclosed 29 additional cases. Morphological, clinical and cytogenetic assessment revealed the typical hallmarks of 3q26/EVI1 rearrangements, that is, trilineage dysplasia and dysmegakaryopoiesis, poor prognosis and additional monosomy 7. Molecular cytogenetic analysis and PCR in selected samples indicated that in most cases the translocation indeed targets the EVI1 locus. Mapping of the chromosome 2 breakpoints confirmed the initially suspected cytogenetic breakpoint heterogeneity at the 2p arm.

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Familial partial trisomy 8p without dysmorphic features and only mild mental retardation

Cited by 32 publications

References 20 publications

Molecular cytogenetic characterization of eight small supernumerary marker chromosomes originating from chromosomes 2, 4, 8,18, and 21 in three patients

Molecular cytogenetic characterization of eight small supernumerary marker chromosomes originating from chromosomes 2, 4, 8,18, and 21 in three patients

Duplications and copy number variants of 8p23.1 are cytogenetically indistinguishable but distinct at the molecular level

Translocation t(2;3)(p15–23;q26–27) in myeloid malignancies: report of 21 new cases, clinical, cytogenetic and molecular genetic features

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