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Hadjipanteli A, Theodosiou A, Papaevripidou I, Evangelidou P, Alexandrou A, Salameh N, Kallikas I, Kakoullis K, Frakala S, Oxinou C, Marnerides A, Kousoulidou L, Anastasiadou VC, Sismani C. Sodium Channel Gene Variants in Fetuses with Abnormal Sonographic Findings: Expanding the Prenatal Phenotypic Spectrum of Sodium Channelopathies. Genes (Basel) 2024; 15:119. [PMID: 38255008 PMCID: PMC10815715 DOI: 10.3390/genes15010119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
Voltage-gated sodium channels (VGSCs) are responsible for the initiation and propagation of action potentials in the brain and muscle. Pathogenic variants in genes encoding VGSCs have been associated with severe disorders including epileptic encephalopathies and congenital myopathies. In this study, we identified pathogenic variants in genes encoding the α subunit of VGSCs in the fetuses of two unrelated families with the use of trio-based whole exome sequencing, as part of a larger cohort study. Sanger sequencing was performed for variant confirmation as well as parental phasing. The fetus of the first family carried a known de novo heterozygous missense variant in the SCN2A gene (NM_001040143.2:c.751G>A p.(Val251Ile)) and presented intrauterine growth retardation, hand clenching and ventriculomegaly. Neonatally, the proband also exhibited refractory epilepsy, spasms and MRI abnormalities. The fetus of the second family was a compound heterozygote for two parentally inherited novel missense variants in the SCN4A gene (NM_000334.4:c.4340T>C, p.(Phe1447Ser), NM_000334.4:c.3798G>C, p.(Glu1266Asp)) and presented a severe prenatal phenotype including talipes, fetal hypokinesia, hypoplastic lungs, polyhydramnios, ear abnormalities and others. Both probands died soon after birth. In a subsequent pregnancy of the latter family, the fetus was also a compound heterozygote for the same parentally inherited variants. This pregnancy was terminated due to multiple ultrasound abnormalities similar to the first pregnancy. Our results suggest a potentially crucial role of the VGSC gene family in fetal development and early lethality.
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Affiliation(s)
- Andrea Hadjipanteli
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | - Athina Theodosiou
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | - Ioannis Papaevripidou
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | - Paola Evangelidou
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | - Angelos Alexandrou
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | - Nicole Salameh
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | | | | | | | - Christina Oxinou
- Christina Oxinou Histopathology/Cytology Laboratory, 1065 Nicosia, Cyprus
| | | | - Ludmila Kousoulidou
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
| | | | - Carolina Sismani
- The Cyprus Institute of Neurology and Genetics, Cytogenetics and Genomics, 2371 Nicosia, Cyprus; (A.H.)
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Alexandrou A, Salameh N, Papaevripidou I, Nicolaou N, Myrianthopoulos P, Ketoni A, Kousoulidou L, Anastasiou AM, Evangelidou P, Tanteles GA, Sismani C. Hereditary multiple exostoses caused by a chromosomal inversion removing part of EXT1 gene. Mol Cytogenet 2023; 16:8. [PMID: 37217936 DOI: 10.1186/s13039-023-00638-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/07/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Hereditary multiple exostoses (HME) is an autosomal dominant skeletal disorder characterized by the development of multiple, circumscript and usually symmetric bony protuberances called osteochondromas. Most HME are caused by EXT1 and EXT2 loss of function mutations. Most pathogenic mutations are nonsense followed by missense mutations and deletions. CASE PRESENTATION Here we report on a patient with a rare and complex genotype resulting in a typical HME phenotype. Initial point mutation screening in EXT1 and EXT2 genes by Sanger sequencing did not reveal any pathogenic variants. The patient along with the healthy parents was subsequently referred for karyotype and array-Comparative Genomic Hybridization (CGH) analyses. Chromosomal analysis revealed two independent de novo apparently balanced rearrangements: a balanced translocation between the long arms of chromosomes 2 and 3 at breakpoints 2q22 and 3q13.2 and a pericentric inversion with breakpoints at 8p23.1q24.1. Both breakpoints were confirmed by Fluorescence In Situ Hybridization (FISH). Subsequently, array-CGH revealed a novel heterozygous deletion within the EXT1 gene at one of the inversion breakpoints, rendering the inversion unbalanced. The mode of inheritance, as well as the size of the deletion were further investigated by Quantitative Real-time PCR (qPCR), defining the deletion as de novo and of 3.1 kb in size, removing exon 10 of EXT1. The inversion in combination with the 8p23.1 deletion most likely abolishes the transcription of EXT1 downstream of exon 10 hence resulting in a truncated protein. CONCLUSIONS The identification of a rare and novel genetic cause of HME, highlights the importance of additional comprehensive investigation of patients with typical clinical manifestations, even when EXT1 and EXT2 mutation analysis is negative.
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Affiliation(s)
- Angelos Alexandrou
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Nicole Salameh
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Nayia Nicolaou
- Clinical Genetics Department, Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Panayiotis Myrianthopoulos
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Andria Ketoni
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Ludmila Kousoulidou
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - Anna-Maria Anastasiou
- Clinical Genetics Department, Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Paola Evangelidou
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus
| | - George A Tanteles
- Clinical Genetics Department, Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Carolina Sismani
- Cytogenetics and Genomics Department, The Cyprus Institute of Neurology and Genetics, 6 Iroon Avenue, 2371, Ayios Dometios, PO Box 23462, 1683, Nicosia, Cyprus.
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Evangelidou P, Kousoulidou L, Salameh N, Alexandrou A, Papaevripidou I, Alexandrou IM, Ketoni A, Ioannidou C, Christophidou-Anastasiadou V, Tanteles GA, Sismani C. An unusual combination of an atypical maternally inherited novel 0.3 Mb deletion in Williams-Beuren region and a de novo 22q11.21 microduplication in an infant with supravalvular aortic stenosis. Eur J Med Genet 2020; 63:104084. [PMID: 33045407 DOI: 10.1016/j.ejmg.2020.104084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/24/2020] [Accepted: 10/04/2020] [Indexed: 12/31/2022]
Abstract
Williams-Beuren syndrome (WBS) is a rare neurodevelopmental disorder characterized by supravalvular aortic stenosis (SVAS), intellectual disability, overfriendliness and dysmorphic features. It is typically caused by 1.5-1.8 Mb deletions on 7q11.23. The 22q11.21 microduplication syndrome has a variable phenotype and is frequently associated with congenital heart disease. Here we present a unique patient, carrying aberrations within both of the above syndrome regions, referred for possible diagnosis of WBS because of SVAS. The patient was a boy who died suddenly 47 days after birth, possibly due to cardiac complications. Genetic testing was carried out, including array Comparative Genomic Hybridization (aCGH), Fluorescence In situ Hybridization (FISH) and Multiplex Ligation-Dependent Probe Amplification (MLPA) showing that the proband was heterozygous for a novel and atypical 0.3 Mb deletion in WBS region (7q11.23) encompassing the ELN gene. In addition, he was found heterozygous for a 22q11.21 microduplication. Parental studies revealed that the 7q11.23 deletion was inherited from the mother who also exhibited a cardiovascular phenotype, however very mild. The same maternally inherited deletion was detected in one of the proband's siblings, born two years later with a less severe SVAS. The 22q11.2 microduplication was de novo in origin. Detection and investigation of atypical deletions within known syndrome regions are crucial for better genotype-phenotype correlations and more accurate characterization of critical regions. The combined effect of two different genetic defects - one in a known syndrome region and one with variable clinical significance, is valuable for revealing gene interactions and enabling more accurate predictions, especially in prenatal diagnosis.
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Affiliation(s)
- Paola Evangelidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus; The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Ludmila Kousoulidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus; The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Nicole Salameh
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioanna-Maria Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Andria Ketoni
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Charithea Ioannidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | | | - George A Tanteles
- Clinical Genetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus; The Cyprus School of Molecular Medicine, Nicosia, Cyprus.
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Alexandrou A, Papaevripidou I, Alexandrou IM, Theodosiou A, Evangelidou P, Kousoulidou L, Tanteles G, Christophidou‐Anastasiadou V, Sismani C. De novo mosaic MECP2 mutation in a female with Rett syndrome. Clin Case Rep 2019; 7:366-370. [PMID: 30847208 PMCID: PMC6389470 DOI: 10.1002/ccr3.1985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/30/2018] [Accepted: 12/11/2018] [Indexed: 01/08/2023] Open
Abstract
We describe a female with Rett syndrome carrying a rare de novo mosaic nonsense mutation on MECP2 gene, with random X-chromosome inactivation. Rett syndrome severity in females depends on mosaicism level and tissue specificity, X-chromosome inactivation, epigenetics and environment. Rett syndrome should be considered in both males and females.
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Affiliation(s)
- Angelos Alexandrou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ioanna Maria Alexandrou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Athina Theodosiou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Paola Evangelidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ludmila Kousoulidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - George Tanteles
- Department of Clinical GeneticsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Violetta Christophidou‐Anastasiadou
- Department of Clinical GeneticsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Archbishop Makarios III Medical CentreNicosiaCyprus
| | - Carolina Sismani
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- The Cyprus School of Molecular MedicineNicosiaCyprus
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Kousoulidou L, Alexandrou A, Papaevripidou I, Evangelidou P, Tanteles G, Anastasiadou VC, Sismani C. Two unrelated individuals carrying rare mosaic deletions in TCF4 gene. Am J Med Genet A 2018; 179:134-138. [PMID: 30450687 PMCID: PMC6587998 DOI: 10.1002/ajmg.a.60692] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 10/15/2018] [Accepted: 10/22/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Ludmila Kousoulidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Paola Evangelidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George Tanteles
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Violetta C Anastasiadou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,Department of Clinical Genetics, Archbishop Makarios III Medical Centre, Nicosia, Cyprus
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,The Cyprus School of Molecular Medicine, Nicosia, Cyprus
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Lederer CW, Pavlou E, Tanteles GA, Evangelidou P, Sismani C, Kolnagou A, Sitarou M, Christou S, Hadjigavriel M, Kleanthous M. Hb A 2 Episkopi - a novel δ-globin chain variant [HBD:c.428C>T] in a family of mixed Cypriot-Lebanese descent. ACTA ACUST UNITED AC 2016; 22:304-309. [PMID: 28007020 DOI: 10.1080/10245332.2016.1265043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Thalassaemia is a potentially lethal inherited anaemia, caused by reduced or absent synthesis of globin chains. Measurement of the minor adult haemoglobin Hb A2, combining α- with δ-globin, is critical for the routine diagnosis of carrier status for α- or β-thalassaemia. Here, we aim to characterize a novel δ-globin variant, Hb A2 Episkopi, in a single family of mixed Lebanese and Cypriot ancestry with mild hypochromic anaemia and otherwise normal globin genotype, which also presents with a coincidental 0.78-Mb sequence duplication on chromosome 1 (1q44) and developmental abnormalities. METHODS Analyses included comprehensive haematological analyses, cation-exchange high-performance liquid chromatography (CE-HPLC), cellulose acetate electrophoresis (CAE), Sanger sequencing and structure-based stability predictions for Hb A2 Episkopi. RESULTS The GCT > GTT missense mutation, underlying Hb A2 Episkopi, HBD:c.428C > T, introduces a cd142 codon change in the mature protein, resulting in reduced normal Hb A2 amounts and a novel, less abundant Hb A2 variant (HGVS: HBD:p.A143V), detectable as a delayed peak by CE-HPLC. The latter was in line with structure-based stability predictions, which indicated that the substitution of a marginal, non-helical and non-interface residue, five amino acids from the δ-globin chain carboxy-terminus, was moderately destabilizing. DISCUSSION Detection of the new variant depends on the diagnostic set-up and had failed by CAE and on an independent CE-HPLC system, which, in unfavourable circumstances, may lead to misdiagnoses of β-thalassaemia as α-thalassaemia. Given the mixed background of the affected family, the ethnic origin of the mutation is unclear, and this study thus suggests awareness for possible detection of Hb A2 Episkopi in both the Cypriot and the Lebanese populations.
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Affiliation(s)
- Carsten W Lederer
- a Department of Molecular Genetics Thalassaemia , The Cyprus Institute of Neurology and Genetics, Cyprus & Cyprus School of Molecular Medicine , Nicosia , Cyprus
| | - Eleni Pavlou
- a Department of Molecular Genetics Thalassaemia , The Cyprus Institute of Neurology and Genetics, Cyprus & Cyprus School of Molecular Medicine , Nicosia , Cyprus
| | - George A Tanteles
- b Clinical Genetics Department , The Cyprus Institute of Neurology and Genetics , Nicosia , Cyprus
| | - Paola Evangelidou
- c Department of Cytogenetics and Genomics , The Cyprus Institute of Neurology and Genetics, Cyprus & Cyprus School of Molecular Medicine , Nicosia , Cyprus
| | - Carolina Sismani
- c Department of Cytogenetics and Genomics , The Cyprus Institute of Neurology and Genetics, Cyprus & Cyprus School of Molecular Medicine , Nicosia , Cyprus
| | | | | | | | | | - Marina Kleanthous
- a Department of Molecular Genetics Thalassaemia , The Cyprus Institute of Neurology and Genetics, Cyprus & Cyprus School of Molecular Medicine , Nicosia , Cyprus
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Tanteles GA, Alexandrou A, Evangelidou P, Gavatha M, Anastasiadou V, Sismani C. PartialMEF2Cdeletion in a Cypriot patient with severe intellectual disability and a jugular fossa malformation: Review of the literature. Am J Med Genet A 2015; 167A:664-9. [DOI: 10.1002/ajmg.a.36945] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/07/2014] [Indexed: 02/06/2023]
Affiliation(s)
- George A. Tanteles
- Clinical Genetics Department; The Cyprus Institute of Neurology and Genetics & Archbishop Makarios III Medical Centre; Nicosia Cyprus
| | - Angelos Alexandrou
- Cytogenetics and Genomics Department; The Cyprus Institute of Neurology and Genetics; Nicosia Cyprus
| | - Paola Evangelidou
- Cytogenetics and Genomics Department; The Cyprus Institute of Neurology and Genetics; Nicosia Cyprus
| | - Marina Gavatha
- Pediatric Neurology Department; Archbishop Makarios III Medical Centre; Nicosia Cyprus
| | - Violetta Anastasiadou
- Clinical Genetics Department; The Cyprus Institute of Neurology and Genetics & Archbishop Makarios III Medical Centre; Nicosia Cyprus
| | - Carolina Sismani
- Cytogenetics and Genomics Department; The Cyprus Institute of Neurology and Genetics; Nicosia Cyprus
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Kitsiou-Tzeli S, Sismani C, Karkaletsi M, Florentin L, Anastassiou A, Koumbaris G, Evangelidou P, Agapitos E, Patsalis PC, Velissariou V. Erratum: Prenatal diagnosis of a de novo
partial trisomy 10p12.1-12.2 pter originating from an unbalanced translocation onto 15qter and confirmed with array CGH. Prenat Diagn 2010. [DOI: 10.1002/pd.2558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kitsiou-Tzeli S, Sismani C, Karkaletsi M, Florentin L, Anastassiou A, Koumbaris G, Evangelidou P, Agapitos E, Patsalis PC, Velissariou V. Prenatal diagnosis of a de novo partial trisomy 10p12.1-12.2 pter originating from an unbalanced translocation onto 15qter and confirmed with array CGH. Prenat Diagn 2008; 28:770-2. [PMID: 18615545 DOI: 10.1002/pd.2049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Velissariou V, Sismani C, Christopoulou S, Kaminopetros P, Hatzaki A, Evangelidou P, Koumbaris G, Bartsocas CS, Stylianidou G, Skordis N, Diakoumakos A, Patsalis PC. Loss of the Y chromosome PAR2 region and additional rearrangements in two familial cases of satellited Y chromosomes: cytogenetic and molecular analysis. Eur J Med Genet 2007; 50:291-300. [PMID: 17584536 DOI: 10.1016/j.ejmg.2007.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 04/10/2007] [Indexed: 10/23/2022]
Abstract
Two cases of rare structural aberrations of the Y chromosome were detected: a del(Y) (q12) chromosome in a child with mild dysmorphic features, obesity and psychomotor delay, and two identical satellited Y chromosomes (Yqs) in a normal twin, which were originally observed during routine prenatal diagnosis. In both cases a Yqs chromosome was detected in the father which had arisen from a reciprocal translocation involving the short arm of chromosome 15 and the heterochromatin of the long arm of the Y chromosome (Yqh). Cytogenetic and molecular studies demonstrated that in the reciprocal product of chromosomes 15 and Y PAR2 could not be detected, showing that PAR2 had been deleted. It is discussed whether the translocation of the short arm of an acrocentric chromosome to the heterochromatin of the long arm of the Y chromosome causes instability of this region which results either in loss of genetic material or interference with the normal mechanism of disjunction.
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Affiliation(s)
- V Velissariou
- Department of Genetics and Molecular Biology, Mitera General, Maternity and Pediatric Clinic, 6 Eryrthrou Street & Kifissias, 15123 Athens, Greece.
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Patsalis PC, Evangelidou P, Charalambous S, Sismani C. Fluorescence in situ hybridization characterization of apparently balanced translocation reveals cryptic complex chromosomal rearrangements with unexpected level of complexity. Eur J Hum Genet 2004; 12:647-53. [PMID: 15162125 DOI: 10.1038/sj.ejhg.5201211] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022] Open
Abstract
The great majority of apparently balanced translocations are associated with multiple miscarriages and normal phenotype. Several mechanisms have been proposed to explain how a small percentage of apparently balanced translocations are associated with abnormal phenotypes. One of the proposed mechanisms that have not been well investigated is that apparently balanced translocations may host 'cryptic' complex chromosomal rearrangements (CCRs). To test this hypothesis, this study investigated 20 non-preselected cases with apparently balanced translocations in order to determine the presence of cryptic CCRs. Multiprobe subtelomeric and whole chromosome paint FISH analyses revealed and further characterized three cryptic CCRs. Two out of three CCRs showed an unexpected level of complexity. The results of this study provided evidence that the link between an apparently balanced rearrangement and the appearance of abnormal phenotype may be partly explained by the presence of cryptic CCRs. The results also suggested that what is reported as apparently balanced translocation by classical cytogenetics may host cryptic CCRs, which could be more common than initially thought. Furthermore, the use of both of the above-mentioned FISH methodologies was absolutely necessary to detect the CCRs.
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Affiliation(s)
- Philippos C Patsalis
- Department of Cytogenetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.
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