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Hu X, Li L, Zhang H, Hu Z, Li L, Sun M, Liu R. Prenatal diagnosis of a de novo tetrasomy 15q24.3-25.3: Case report and literature review. J Clin Lab Anal 2020; 34:e23288. [PMID: 32185823 PMCID: PMC7370735 DOI: 10.1002/jcla.23288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/02/2020] [Accepted: 02/21/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Terminal duplication on chromosome 15q is a rare chromosomal variation. Affected individuals show similar features such as growth dysplasia or the development of frontal bossing, body deformities, facial abnormalities, and genitourinary or cardiovascular disorders. However, it is not yet clear whether such 15q repeats lead to identifiable patterns of clinical abnormalities. Therefore, the purpose of this study was to analyze the prenatal diagnostic results and clinical manifestations of a fetus with 15q duplication and to summarize the literature. METHODS The case was a fetus at 28 weeks of gestation. The risk of Down syndrome from second-trimester screening was 1/140. Prenatal ultrasound and amniocentesis were performed, and chromosomal microarray analysis (CMA) was used for genetic analysis. RESULTS The fetus had abnormal clinical features, including intracardiac echogenic focus in the left ventricle, an aberrant right subclavian artery, and growth delay. The fetal chromosomal karyotype was 46,XX,15q?,12q?,21pstk+, and CMA revealed a 10.163 Mb duplication at 15q24.3-q25.3. The couple chose to terminate the pregnancy after careful consideration. CONCLUSIONS The combination and rational application of cytogenetics technology and molecular genetics technology such as CMA will open up the field of clinical application and provide useful genetic counseling for parents of fetuses carrying such chromosomal duplications.
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Affiliation(s)
- Xiaonan Hu
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Leilei Li
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Hongguo Zhang
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Zhuming Hu
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Linlin Li
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Meiling Sun
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Ruizhi Liu
- Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.,Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
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Ochando I, Alonzo Martínez MC, Serrano AM, Urbano A, Cazorla E, Calvo D, Rueda J. Prenatal diagnosis and molecular cytogenetic characterization of a de novo duplication of 15q24.3-q26.1. APPLICATION OF CLINICAL GENETICS 2018; 11:77-80. [PMID: 30013380 PMCID: PMC6037148 DOI: 10.2147/tacg.s159377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reported cases of distal 15q interstitial duplications are uncommon and do not result in a recognizable pattern of abnormalities. Some studies report prenatal overgrowth, while others describe growth retardation. We present molecular cytogenetic characterization of a 14 Mb interstitial duplication, encompassing 81 Online Mendelian Inheritance in Man (OMIM) genes, in a fetus with single umbilical artery and short limbs. We propose that growth restriction, previously described and present in our patient, may be due to duplication of a gene or genes contained in the 15q24 region.
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Affiliation(s)
- Isabel Ochando
- Genetics Unit, Unidad de Genética, Hospital Clínica Vistahermosa, Alicante, Spain, .,Departamento de Histología y Anatomía, Universidad Miguel Hernández, Alicante, Spain,
| | - Melanie Cristine Alonzo Martínez
- Department of Obstetrics and Gynecology, Servicio de Ginecología y Obstetricia, Hospital Universitario de Torrevieja, Alicante, Spain
| | - Ana María Serrano
- Department of Obstetrics and Gynecology, Servicio de Ginecología y Obstetricia, Hospital Universitario de Torrevieja, Alicante, Spain
| | - Antonio Urbano
- Genetics Unit, Unidad de Genética, Hospital Clínica Vistahermosa, Alicante, Spain,
| | - Eduardo Cazorla
- Department of Obstetrics and Gynecology, Servicio de Ginecología y Obstetricia, Hospital Universitario de Torrevieja, Alicante, Spain
| | - Dolores Calvo
- Emergency Laboratory, Laboratorio Urgencias, Hospital Clínico Universitario, Valladolid, Spain
| | - Joaquín Rueda
- Genetics Unit, Unidad de Genética, Hospital Clínica Vistahermosa, Alicante, Spain, .,Departamento de Histología y Anatomía, Universidad Miguel Hernández, Alicante, Spain,
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3
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Cannarella R, Mattina T, Condorelli RA, Mongioì LM, Pandini G, La Vignera S, Calogero AE. Chromosome 15 structural abnormalities: effect on IGF1R gene expression and function. Endocr Connect 2017; 6:528-539. [PMID: 28899882 PMCID: PMC5597972 DOI: 10.1530/ec-17-0158] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 12/27/2022]
Abstract
Insulin-like growth factor 1 receptor (IGF1R), mapping on the 15q26.3 chromosome, is required for normal embryonic and postnatal growth. The aim of the present study was to evaluate the IGF1R gene expression and function in three unrelated patients with chromosome 15 structural abnormalities. We report two male patients with the smallest 15q26.3 chromosome duplication described so far, and a female patient with ring chromosome 15 syndrome. Patient one, with a 568 kb pure duplication, had overgrowth, developmental delay, mental and psychomotor retardation, obesity, cryptorchidism, borderline low testis volume, severe oligoasthenoteratozoospermia and gynecomastia. We found a 1.8-fold increase in the IGF1R mRNA and a 1.3-fold increase in the IGF1R protein expression (P < 0.05). Patient two, with a 650 kb impure duplication, showed overgrowth, developmental delay, mild mental retardation, precocious puberty, low testicular volume and severe oligoasthenoteratozoospermia. The IGF1R mRNA and protein expression was similar to that of the control. Patient three, with a 46,XX r(15) (p10q26.2) karyotype, displayed intrauterine growth retardation, developmental delay, mental and psychomotor retardation. We found a <0.5-fold decrease in the IGF1R mRNA expression and an undetectable IGF1R activity. After reviewing the previously 96 published cases of chromosome 15q duplication, we found that neurological disorders, congenital cardiac defects, typical facial traits and gonadal abnormalities are the prominent features in patients with chromosome 15q duplication. Interestingly, patients with 15q deletion syndrome display similar features. We speculate that both the increased and decreased IGF1R gene expression may play a role in the etiology of neurological and gonadal disorders.
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Affiliation(s)
- Rossella Cannarella
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
| | | | - Rosita A Condorelli
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
| | - Laura M Mongioì
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
| | - Giuseppe Pandini
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
| | - Sandro La Vignera
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
| | - Aldo E Calogero
- Department of Clinical and Experimental MedicineUniversity of Catania, Catania, Italy
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Mapping Breakpoints of Complex Chromosome Rearrangements Involving a Partial Trisomy 15q23.1-q26.2 Revealed by Next Generation Sequencing and Conventional Techniques. PLoS One 2016; 11:e0154574. [PMID: 27218255 PMCID: PMC4878739 DOI: 10.1371/journal.pone.0154574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/16/2016] [Indexed: 11/25/2022] Open
Abstract
Complex chromosome rearrangements (CCRs), which are rather rare in the whole population, may be associated with aberrant phenotypes. Next-generation sequencing (NGS) and conventional techniques, could be used to reveal specific CCRs for better genetic counseling. We report the CCRs of a girl and her mother, which were identified using a combination of NGS and conventional techniques including G-banding, fluorescence in situ hybridization (FISH) and PCR. The girl demonstrated CCRs involving chromosomes 3 and 8, while the CCRs of her mother involved chromosomes 3, 5, 8, 11 and 15. HumanCytoSNP-12 Chip analysis identified a 35.4 Mb duplication on chromosome 15q21.3-q26.2 in the proband and a 1.6 Mb microdeletion at chromosome 15q21.3 in her mother. The proband inherited the rearranged chromosomes 3 and 8 from her mother, and the duplicated region on chromosome 15 of the proband was inherited from the mother. Approximately one hundred genes were identified in the 15q21.3-q26.2 duplicated region of the proband. In particular, TPM1, SMAD6, SMAD3, and HCN4 may be associated with her heart defects, and HEXA, KIF7, and IDH2 are responsible for her developmental and mental retardation. In addition, we suggest that a microdeletion on the 15q21.3 region of the mother, which involved TCF2, TCF12, ADMA10 and AQP9, might be associated with mental retardation. We delineate the precise structures of the derivative chromosomes, chromosome duplication origin and possible molecular mechanisms for aberrant phenotypes by combining NGS data with conventional techniques.
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Trisomy Xp and partial tetrasomy Xq resulting from gain of a rearranged X chromosome in a female fetus: pathogenic or not? Mol Cytogenet 2015. [PMID: 26213575 PMCID: PMC4513972 DOI: 10.1186/s13039-015-0160-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cytogenetic analysis of chorionic villous sampling revealed a mosaic karyotype with gain of a rearranged X chromosome. Microarray and additional studies indicated that the rearranged X carried an inverted duplication, a deletion and a satellited Xqter. Gain of this rearranged X was confirmed by follow-up amniocentesis and postnatal cord blood sample. A full-term infant girl was delivered and showed normal physical findings at both birth and 21-month follow-up examinations. Late replication studies demonstrated that the rearranged X was inactivated in all abnormal cells analyzed. Skewed X-inactivation may suppress the potentially deleterious effects of genomic imbalance; however, gain of X chromosomes, particularly rearranged X chromosomes, often presents challenges for prenatal genetic counseling. The gradation of clinical phenotype severity generally correlates with the number of additional X chromosomes. However, the X chromosome regions responsible for the abnormal phenotypes are poorly understood. This case will further elucidate the phenotypic effects of X inactivation and X chromosome abnormalities.
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Chen CP, Lin YH, Au HK, Su YN, Hsu CY, Liu YP, Wu PC, Chern SR, Chen YT, Chen LF, Hsieh AHM, Wang W. Chromosome 15q overgrowth syndrome: Prenatal diagnosis, molecular cytogenetic characterization, and perinatal findings in a fetus with dup(15)(q26.2q26.3). Taiwan J Obstet Gynecol 2011; 50:359-65. [DOI: 10.1016/j.tjog.2011.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2011] [Indexed: 12/11/2022] Open
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Chen CP, Su YN, Chern SR, Hsu CY, Tsai FJ, Wu PC, Lee CC, Chen YT, Lee MS, Wang W. Inv dup del(9p): prenatal diagnosis and molecular cytogenetic characterization by fluorescence in situ hybridization and array comparative genomic hybridization. Taiwan J Obstet Gynecol 2011; 50:67-73. [PMID: 21482378 DOI: 10.1016/j.tjog.2011.01.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2010] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To present molecular cytogenetic characterization of prenatally detected inverted duplication and deletion of 9p, or inv dup del(9p). MATERIALS, METHODS, AND RESULTS A 35-year-old primigravid woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a derivative chromosome 9, or der(9) with additional material at the end of the short arm of one chromosome 9. Parental karyotypes were normal. Level II ultrasound showed ventriculomegaly and normal male external genitalia. Repeated amniocentesis was performed at 20 weeks of gestation. Array comparative genomic hybridization revealed a 0.70-Mb deletion at 9p24.3 and an 18.36-Mb duplication from 9p24.3 to 9p22.1. The distal 9p deletion encompassed the genes of DOCK8, ANKRD15, FOXD4, DMRT1, and DMRT3. Fluorescence in situ hybridization analysis using bacterial artificial chromosome clone probes specific for 9p confirmed that the der(9) was derived from the inv dup del(9p). The karyotype of the fetus was 46,XY,inv dup del(9)(:p22.1-->p24.3::p24.3-->qter)dn or 46,XY,der(9) del(9)(p24.3) inv dup(9)(p22.1p24.3)dn. Polymorphic DNA marker analysis determined a maternal origin of the inv dup del(9p). A 512-g male fetus was subsequently terminated at 22 weeks of gestation with facial dysmorphism. The fetus had normal male external genitalia without sex reversal. CONCLUSION Fluorescence in situ hybridization and array comparative genomic hybridization are useful to determine the nature of a prenatally detected aberrant chromosome derived from the inv dup del. Male fetuses with inv dup del(9p) and haploinsufficiency of DMRT1 and DMRT3 may present normal male external genitalia without sex reversal.
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Affiliation(s)
- Chih-Ping Chen
- Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
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Kim EY, Kim YK, Kim MK, Jung JM, Jeon GW, Kim HR, Sin JB. A case of de novo duplication of 15q24-q26.3. KOREAN JOURNAL OF PEDIATRICS 2011; 54:267-71. [PMID: 21949522 PMCID: PMC3174363 DOI: 10.3345/kjp.2011.54.6.267] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 11/11/2010] [Accepted: 12/10/2010] [Indexed: 11/29/2022]
Abstract
Distal duplication, or trisomy 15q, is an extremely rare chromosomal disorder characterized by prenatal and postnatal overgrowth, mental retardation, and craniofacial malformations. Additional abnormalities typically include an unusually short neck, malformations of the fingers and toes, scoliosis and skeletal malformations, genital abnormalities, particularly in affected males, and, in some cases, cardiac defects. The range and severity of symptoms and physical findings may vary from case to case, depending upon the length and location of the duplicated portion of chromosome 15q. Most reported cases of duplication of the long arm of chromosome 15 frequently have more than one segmental imbalance resulting from unbalanced translocations involving chromosome 15 and deletions in another chromosome, as well as other structural chromosomal abnormalities. We report a female newborn with a de novo duplication, 15q24-q26.3, showing intrauterine overgrowth, a narrow asymmetric face with down-slanting palpebral fissures, a large, prominent nose, and micrognathia, arachnodactyly, camptodactyly, congenital heart disease, hydronephrosis, and hydroureter. Chromosomal analysis showed a 46,XX,inv(9)(p12q13),dup(15)(q24q26.3). Array comparative genomic hybridization analysis revealed a gain of 42 clones on 15q24-q26.3. This case represents the only reported patient with a de novo 15q24-q26.3 duplication that did not result from an unbalanced translocation and did not have a concomitant monosomic component in Korea.
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Affiliation(s)
- Eun Young Kim
- Department of Pediatrics, Pusan Paik Hospital, Inje University College of Medicine, Busan, Korea
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Vera-Carbonell A, López-Expósito I, Bafalliu JA, Ballesta-Martínez M, Glóver G, Llópis C, Moya-Quiles R, Suela J, Fernández A, Guillén-Navarro E. Molecular characterization of a new patient with a non-recurrent inv dup del 2q and review of the mechanisms for this rearrangement. Am J Med Genet A 2010; 152A:2670-80. [PMID: 20799321 DOI: 10.1002/ajmg.a.33613] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report on newborn baby with microcephaly, facial anomalies, congenital heart defects, hypotonia, wrist contractures, long fingers, adducted thumbs, and club feet. Cytogenetic studies revealed an inverted duplication with terminal deletion (inv dup del) of 2q in the patient and a paternal 2qter deletion polymorphism. Microsatellite markers demonstrated that the inv dup del was maternal in origin and intrachromosomal. Intra or interchromosomal rearrangements may cause this aberration either by a U-type exchange (end-to-end fusion), an unequal crossover between inverted repeats (non-allelic homologous recombination: NAHR), or through breakage-fusion-bridge (BFB) cycles leading to a sister chromatid fusion by non-homologous end joining (NHEJ). A high-resolution oligo array-CGH (244 K) defined the breakpoints and did not detect a single copy region with a size exceeding 12.93 Kb in the fusion site. The size of the duplicated segment was 38.75 Mb, extending from 2q33.1 to 2q37.3 and the size of the terminal deletion was 2.85 Mb in 2q37.3. Our results indicate that the inv dup del (2q) is likely a non-recurrent chromosomal rearrangement generated by a NHEJ mechanism. The major clinical characteristics associated with this 2q rearrangement overlap with those commonly found in patients with 2q duplication reported in the literature.
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Affiliation(s)
- Ascensión Vera-Carbonell
- Sección de Citogenética, Centro de Bioquímica y Genética Clínica, Hospital U. Virgen de la Arrixaca, Murcia, Spain
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Gutiérrez-Franco MDLA, Madariaga-Campos MDLL, Vásquez-Velásquez AI, Matute E, Guevara-Yáñez R, Rivera H. A girl with 15q overgrowth syndrome and dup(15)(q24q26.3) that included telomeric sequences. Korean J Lab Med 2010; 30:318-24. [PMID: 20603595 DOI: 10.3343/kjlm.2010.30.3.318] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Distal 15q trisomy or tetrasomy is associated with a characteristic phenotype that includes mild to moderate intellectual disability, abnormal behavior, speech impairment, overgrowth, hyperlaxity, long face, prominent nose, puffy cheeks, pointed chin, small ears, and hand anomalies (mainly arachno- and camptodactyly). We present the case of a 13-yr-old girl with the main clinical features of 15q overgrowth syndrome and a 46,XX,dup(15)(q24q26.3)[117]/46,XX[3].ish dup(15)(q24q26.3) (SNPRN+,PML+,subtel++,tel++) de novo karyotype. The findings in this case are consistent with those in the previous distal 15q trisomy cases that presented with overgrowth and mental retardation. Further, the rearranged chromosome had a double set of directly oriented telomeric and subtelomeric sequences.
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Zuffardi O, Bonaglia M, Ciccone R, Giorda R. Inverted duplications deletions: underdiagnosed rearrangements?? Clin Genet 2009; 75:505-13. [PMID: 19508415 DOI: 10.1111/j.1399-0004.2009.01187.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Molecular techniques led to the discovery that several chromosome rearrangements interpreted as terminal duplications were in fact inverted duplications contiguous to terminal deletions. Inv dup del rearrangements originate through a symmetric dicentric chromosome that, after asymmetric breakage, generates an inv dup del and a deleted chromosome. In recurrent inverted duplications the dicentric chromosome is formed at meiosis through non-allelic homologous recombination. In non-recurrent inv dup del cases, dicentric intermediates are formed by non-homologous end joining or intrastrand annealing. Some authors hypothesized that in these cases the dicentric may have been formed directly in the zygote. Healing of the broken dicentric chromosomes can occur not only in a telomerase-dependent way but also through telomere capture and circularization thus creating translocated or ring inv dup del chromosomes. In all the cases reported up to now, the duplicated region was always longer than the deleted one, but we can safely assume that there is another group of rearrangements where the deleted region is longer than the duplicated portion. In general, in these cases, the cytogeneticist will suspect the presence of a deletion and confirm it by FISH with a subtelomeric probe, but he/she will almost certainly miss the duplication. It is likely that the conventional analysis techniques used until now have led to a substantial underestimate of the frequency of inv dup del rearrangements and that the widespread use of array-CGH in routine analysis will allow a more realistic estimate. Obviously, the concomitant presence of deletion and duplication has important consequences in genotype/phenotype correlations.
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Affiliation(s)
- O Zuffardi
- Biologia Generale e Genetica Medica, Università di Pavia, Pavia, Italy.
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Paskulin GA, Riegel M, Cotter PD, Kiss A, Rosa RFM, Zen PRG, Mombach R, Graziadio C. Inv dup del(4)(:p13-->p16.3::p16.3-->qter) in a girl without typical manifestations of Wolf-Hirschhorn syndrome. Am J Med Genet A 2009; 149A:1302-7. [PMID: 19449429 DOI: 10.1002/ajmg.a.32888] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report on a 4-year-old girl who presented with microcephaly, multiple minor anomalies of face and limbs, congenital heart defect, hypotonia, neuropsychomotor delay, deafness and seizures. A GTG-banded karyotype identified an additional fragment of unknown origin on the terminal region of 4p. Parental karyotypes were normal. FISH analysis using a whole chromosome paint probe for chromosome 4 and subtelomere probes showed a signal on the entire add (4) chromosome and loss of the 4p subtelomere region, respectively. Additional analysis using microsatellite markers for chromosome 4 and whole-genome array comparative genomic hybridization (array-CGH) identified a duplication of the region 4p13 --> 4p16.3. Her karyotype was thus interpreted as an inverted duplication with terminal deletion of 4p: 46,XX,der(4)(:p13 --> p16.3::p16.3 --> qter). The clinical features of our patient differed from those typically observed in Wolf-Hirschhorn syndrome and were more compatible with duplication 4(p14 --> p16.3), with preservation of the WHS critical region.
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Affiliation(s)
- Giorgio A Paskulin
- Clinical Genetics, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Complexo Hospitalar Santa Casa de Porto Alegre (CHSCPA), Porto Alegre, RS, Brazil
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Leclercq S, Maincent K, Baverel F, Tessier DL, Letourneur F, Lebbar A, Dupont JM. Molecular cytogenetic characterization of the first reported case of inv dup del 20p compatible with a U-type exchange model. Am J Med Genet A 2009; 149A:437-45. [PMID: 19206177 DOI: 10.1002/ajmg.a.32640] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Inverted duplications with terminal deletions have been reported for an increasing number of chromosome ends. The best characterized and most frequent rearrangement reported involves the short arm of chromosome 8. It derives from non-allelic homologous recombination (NAHR) between two inverted LCRs (low copy repeats) of the olfactory receptor (OR) gene cluster during maternal meiosis. We report here on the cytogenetic characterization of the first inversion duplication deletion involving the short arm of chromosome 20 (inv dup del 20p) in an 18-month-old boy presenting with clinical signs consistent with 20p trisomy syndrome. This abnormality was suspected on karyotyping, but high-resolution molecular cytogenetic investigations were required to define the breakpoints of the rearrangement and to obtain insight into the mechanism underlying its formation. The duplicated region was estimated to be 18.16 Mb in size, extending from 20p13 to 20p11.22, and the size of the terminal deletion was estimated at 2.02 Mb in the 20p13 region. No single copy region was detected between the deleted and duplicated segments. As neither LCR nor inversion was identified in the 20p13 region, the inv dup del (20p) chromosome abnormality probably did not arise by NAHR. The most likely mechanism involves a break in the 20p13 region, leading to chromosome instability and reparation by U-type exchange or end-to-end fusion.
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Affiliation(s)
- Sandrine Leclercq
- AP-HP, Université Paris-Descartes, Faculté de médecine Unité de Cytogénétique, Groupe Hospitalier Cochin-Saint Vincent de Paul, Paris, France.
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Wang JC, Coe BP, Lomax B, MacLeod PM, Parslow MI, Schein JE, Lam WL, Eydoux P. Inverted duplication with terminal deletion of 5p and no cat-like cry. Am J Med Genet A 2008; 146A:1173-9. [PMID: 18266247 DOI: 10.1002/ajmg.a.32246] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report on a 6-year-old boy referred for cytogenetics study. A few non-specific features were observed in the newborn: hypotonia, failure to thrive, seizures, pre-auricular skin tags. Cat-like cry was not identified. No remarkable facial dysmorphism, gastrointestinal, respiratory or cardiac abnormalities were identified. At age 4 years, speech and motor skill delays were apparent. Karyotyping and FISH analysis revealed a de novo rearranged chromosome 5p, with subtelomeric deletion of 5p and a duplication of the cri-du-chat critical region. Array CGH using sub-megabase resolution tiling-set (SMRT) array followed by FISH analysis with labeled BACs showed a deletion of 5pter to 5p15.31 (0-6.9 Mb) and an inverted duplication of the greater part of 5p15.31 to the distal end of 5p14.3 (6.9-19.9 Mb). Although very rare, inverted duplications with terminal deletion (inv dup del) have been reported at different chromosomal ends. Our finding adds a second patient of inv dup del 5p to this growing list, and the potential causative mechanisms for this rearrangement are discussed. Review of the mapping information of cri-du-chat patients and the comparison with a previously reported patient suggested that the critical region for cat-like cry is located within a 0.6 Mb region.
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Affiliation(s)
- Jia-Chi Wang
- Cytogenetics Laboratory, Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario, Canada.
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