1
|
Phillips EA, Caluseriu O, Schlade-Bartusiak K, Chernos J, McLeod DR, Thomas MA. Clinical and molecular characterization of an almost complete ring chromosome 4 in two sisters, with recurrence due to gonadal mosaicism. Clin Dysmorphol 2021; 30:173-176. [PMID: 34417371 DOI: 10.1097/mcd.0000000000000382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Autosomal ring chromosomes are rare cytogenetic findings that arise from breakage and fusion of the chromosome ends. Rings are mitotically unstable, usually sporadic and associated with a 'ring syndrome', characterized by a variable phenotype: growth retardation, no significant dysmorphisms and normal to moderately disabled intelligence. We describe the clinical features and molecular characterization of two sisters with ring chromosome 4. Karyotype analysis was performed on both sisters and parents. Chromosome microarray was performed on both sisters to delineate the breakpoint imbalance. Both sisters had a large ring 4 chromosome in the majority of cells analyzed on karyotype. Microarray results were identical in the sisters, showing a 55.8 kb duplication on the terminal 4p arm and a 1.5 Mb deletion on the terminal 4q arm. No genes of interest were identified in these regions. Parental karyotypes on lymphocytes and fibroblasts were normal, with no finding of mosaicism for the ring 4 chromosome. Polymorphic marker analysis revealed the maternal origin of the ring. To our knowledge, this is the first reported instance of a ring 4 chromosome recurring in siblings after extensive parental testing, which suggests this was due to maternal gonadal mosaicism.
Collapse
Affiliation(s)
- Eliza A Phillips
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary
| | - Oana Caluseriu
- Department of Medical Genetics
- Department of Pediatrics, University of Alberta, Edmonton
| | | | - Judy Chernos
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary
| | - D Ross McLeod
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary
| | - Mary Ann Thomas
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| |
Collapse
|
2
|
Paz-Y-Miño C, Proaño A, Verdezoto SD, García JL, Hernández-Rivas JM, Leone PE. Clinical, cytogenetic, and molecular findings in a patient with ring chromosome 4: case report and literature review. BMC Med Genomics 2019; 12:167. [PMID: 32293439 PMCID: PMC7087353 DOI: 10.1186/s12920-019-0614-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 11/06/2019] [Indexed: 11/11/2022] Open
Abstract
Background Since 1969, 49 cases have been presented on ring chromosome 4. All of these cases have been characterized for the loss of genetic material. The genes located in these chromosomal regions are related to the phenotype. Case presentation A 10-year-old Ecuadorian Mestizo girl with ring chromosome 4 was clinically, cytogenetically and molecularly analysed. Clinical examination revealed congenital anomalies, including microcephaly, prominent nose, micrognathia, low set ears, bilateral clinodactyly of the fifth finger, small sacrococcygeal dimple, short stature and mental retardation. Cytogenetic studies showed a mosaic karyotype, mos 46,XX,r(4)(p16.3q35.2)/46,XX, with a ring chromosome 4 from 75 to 79% in three studies conducted over ten years. These results were confirmed by fluorescence in situ hybridization (FISH). Loss of 1.7 Mb and gain of 342 kb in 4p16.3 and loss of 3 Mb in 4q35.2 were identified by high-resolution mapping array. Conclusion Most cases with ring chromosome 4 have deletion of genetic material in terminal regions; however, our case has inv dup del rearrangement in the ring chromosome formation. Heterogeneous clinical features in all cases reviewed are related to the amount of genetic material lost or gained. The application of several techniques can increase our knowledge of ring chromosome 4 and its deviations from typical “ring syndrome.”
Collapse
Affiliation(s)
- César Paz-Y-Miño
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE. Av. Mariscal Sucre y Av. Mariana de Jesús, Sede Occidental, Bloque I, 2 floor, 170129, Quito, Ecuador.
| | - Ana Proaño
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE. Av. Mariscal Sucre y Av. Mariana de Jesús, Sede Occidental, Bloque I, 2 floor, 170129, Quito, Ecuador
| | - Stella D Verdezoto
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE. Av. Mariscal Sucre y Av. Mariana de Jesús, Sede Occidental, Bloque I, 2 floor, 170129, Quito, Ecuador
| | - Juan Luis García
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-SACYL-CSIC, Salamanca, Spain.,Molecular Medicine Unit, Department of Medicine, Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain
| | - Jesús María Hernández-Rivas
- Molecular Medicine Unit, Department of Medicine, Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain.,Servicio de Hematología, Hospital Universitario de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Paola E Leone
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE. Av. Mariscal Sucre y Av. Mariana de Jesús, Sede Occidental, Bloque I, 2 floor, 170129, Quito, Ecuador.
| |
Collapse
|
3
|
Burgemeister AL, Daumiller E, Dietze-Armana I, Klett C, Freiberg C, Stark W, Lingen M, Centonze I, Rettenberger G, Mehnert K, Zirn B. Continuing role for classical cytogenetics: Case report of a boy with ring syndrome caused by complete ring chromosome 4 and review of literature. Am J Med Genet A 2017; 173:727-732. [PMID: 28127864 DOI: 10.1002/ajmg.a.38063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 11/14/2016] [Indexed: 11/08/2022]
Abstract
Constitutional ring chromosomes can be found for all human chromosomes and are very rare chromosomal abnormalities. A complete ring chromosome without loss of genetic material results from fusion of subtelomeric regions or telomere-telomere fusion. In cases of complete ring chromosome, an increased incidence of severe growth failure with no or only minor anomalies has been observed and attributed to ring syndrome. Ring syndrome is thought to be caused by "dynamic mosaicism" due to ring instability. We report a 6-year-old boy with de novo ring chromosome 4 and typical characteristics of the ring syndrome, namely, proportionate severe growth failure, microcephaly, and minor anomalies. Cytogenetic studies showed complete ring chromosome 4 with mitotic instability. Microarray gave normal results, thus excluding the loss of detectable genetic material. The literature of complete ring chromosome 4 is reviewed. Our case report supports the theory of ring syndrome. No studies about the effects and possible side effects of growth hormone therapy on patients with ring chromosomes have yet been published. We suggest that cytogenetic monitoring of the rate of secondary aberrations in patients with ring chromosome undergoing growth hormone therapy might be feasible. Since the diagnosis would have been missed by molecular karyotyping, our case report underlines the continuing role of classical cytogenetics for the evaluation of structural chromosomal abnormalities in patients with mental and/or physical anomalies. Standard karyotyping is still indispensable and should have an ongoing role as first-tier analysis together with molecular karyotyping. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - Eva Daumiller
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| | - Ilona Dietze-Armana
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| | - Christine Klett
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| | - Clemens Freiberg
- Department of Pediatrics and Adolescent Medicine, Pediatric Endocrinology, University Medicine, Göttingen, Germany
| | - Wiebke Stark
- Department of Pediatrics and Adolescent Medicine, Pediatric Neurology, University Medicine, Göttingen, Germany
| | - Michael Lingen
- Department of Pediatrics and Adolescent Medicine, Pediatric Neurology, University Medicine, Göttingen, Germany
| | - Izabela Centonze
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| | | | - Karl Mehnert
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| | - Birgit Zirn
- Genetikum, Genetic Counseling and Diagnostics, Stuttgart and Neu-Ulm, Germany
| |
Collapse
|
4
|
Ring Chromosome 4 in a Child with Multiple Congenital Abnormalities: A Case Report and Review of the Literature. Case Rep Genet 2016; 2016:4645716. [PMID: 27610251 PMCID: PMC5004004 DOI: 10.1155/2016/4645716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/20/2016] [Indexed: 11/18/2022] Open
Abstract
A female child born preterm with intrauterine growth retardation and presenting with facial dysmorphism with clefts, microcephaly, limb deformities, and congenital abnormalities involving cardiovascular and urinary systems is described. Chromosomal analysis showed a de novo 46,XX,r(4)(p15.3q35) karyotype. The clinical features of the patient were compared with the phenotypic characteristics of 17 previously reported cases with ring chromosome 4 and those with Wolf-Hirschhorn syndrome (4p-). Clinical features observed in this case are consistent with the consensus phenotype in ring chromosome 4. Patent ductus arteriosus and bilateral talipes equinovarus observed in this baby widen the phenotypic spectrum associated with ring chromosome 4.
Collapse
|
5
|
Abstract
Ring chromosomes arise following breakage and rejoining in both chromosome arms. They are heterogeneous with variable size and genetic content and can originate from any chromosome. Phenotypes associated with ring chromosomes are highly variable as apart from any deletion caused by ring formation, imbalances from ring instability can also occur. Of interest is ring chromosome 20 which has a significant association with epilepsy with seizure onset in early childhood. Severe growth deficiency without major malformations is a common finding in the ring chromosome carrier. This phenotype associated with ring behaviour and mitotic instability and independent of the chromosome involved has been termed the "ring syndrome". Precise genotype-phenotype correlations for ring chromosomes may not be possible as influencing factors vary depending on the extent of deletion in ring formation, ring instability and the level of mosaicism. Although ring chromosomes usually arise as de novo events, familial transmission of rings from carrier to offspring has been described and prenatal diagnosis for any pregnancies should always be considered.
Collapse
Affiliation(s)
- Moh-Ying Yip
- SEALS Genetics Laboratory, NSW Health Pathology, Prince of Wales Hospital, Randwick, Sydney, NSW 2031, Australia
| |
Collapse
|
6
|
Rivera H, Domínguez MG. Variegated aneuploidy and ring chromosome syndromes overlap. Am J Med Genet A 2009; 152A:228-9. [PMID: 20034077 DOI: 10.1002/ajmg.a.33195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Horacio Rivera
- División de Genética, CIBO, Instituto Mexicano del Seguro Social, Ap. Postal 1-3838, Guadalajara, Mexico.
| | | |
Collapse
|
7
|
Calabrese G, Giannotti A, Mingarelli R, Gilio MCD, Piemontese MR, Palka G. Case Report: Two newborns with chromosome 4 imbalances: deletion 4q33 → q35 and ring r (4) (pterq35.2-qter). Clin Genet 2008. [DOI: 10.1111/j.1399-0004.1997.tb02467.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
8
|
Zou YS, Van Dyke DL, Thorland EC, Chhabra HS, Michels VV, Keefe JG, Lega MA, Feely MA, Uphoff TS, Jalal SM. Mosaic ring 20 with no detectable deletion by FISH analysis: Characteristic seizure disorder and literature review. Am J Med Genet A 2006; 140:1696-706. [PMID: 16835934 DOI: 10.1002/ajmg.a.31332] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ring chromosome 20 is a rare chromosome disorder characterized by a typical seizure phenotype consisting of complex partial seizures, frequent progression to generalized tonic or tonic-clonic seizures, and nocturnal frontal lobe seizures with frequent episodes of non-convulsive status epilepticus. Development may be normal or mildly delayed, followed by cognitive and behavioral decline after seizure onset. Here, we describe a patient with a typical severe seizure phenotype and a mosaic ring chromosome 20 without loss of p or q subtelomere regions or telomeric sequences. The ring had a longer telomere length than either of the telomere ends of its homologous chromosome 20 by quantitative fluorescence in situ hybridization analysis, suggesting that it might be derived from telomere-telomere fusion. The phenotypic comparison of this patient and other chromosome 20 cases that had terminal deletions of 20qter (n = 1) and 20pter (n = 7), shows that the epilepsy phenotype and electroencephalographic abnormalities are characteristic in patients with ring chromosome 20. Several hypotheses have been proposed to address the elusive mechanisms underlying the seizure disorder in ring chromosome 20. These possibilities include haploinsufficiency of two epilepsy genes CHRNA4 and KCNQ2 located at 20qter, silencing of these genes by a telomere position effect, or microdeletions or rearrangements of genetic material during the ring formation.
Collapse
Affiliation(s)
- Ying S Zou
- Cytogenetics Laboratory, Mayo Clinic, Rochester, Minnesota 55905, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Balci S, Engiz O, Aktaş D, Vargel I, Beksaç MS, Mrasek K, Vermeesch J, Liehr T. Ring chromosome 4 and Wolf–Hirschhorn syndrome (WHS) in a child with multiple anomalies. Am J Med Genet A 2006; 140:628-32. [PMID: 16470698 DOI: 10.1002/ajmg.a.31131] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We report on a 16-month-old male patient with ring chromosome 4 and deletion of Wolf-Hirschhorn syndrome (WHS) region with multiple congenital anomalies including unilateral cleft lip and palate, iris coloboma, microcephaly, midgut malrotation, hypospadias, and double urethral orifices. Peripheral chromosome analysis of the patient showed 46,XY,r(4)(p16.3q35) de novo. Multicolor fluorescence in situ hybridization (FISH) study was also performed and according to multicolor banding (MCB) a r(4)(::p16.3 --> q34.3 approximately 35.1::) was found in all metaphases. Subtelomeric 4p region, subtelomeric 4q region, as well as, Wolf-Hirschhorn critical region were deleted in ring chromosome 4. Genomic microarray analysis was also performed to delineate the size of deletion. Cranial magnetic resonance imaging (MRI) showed hypoplastic corpus callosum, delayed myelinization, and frontal and occipital lobe atrophies. Both maternal and paternal chromosomal analyses were normal. We compare the phenotypic appearance of our patient with the previously reported 16 cases of ring chromosome 4 in the medical literature.
Collapse
Affiliation(s)
- Sevim Balci
- Department of Clinical Genetics, Hacettepe University Faculty of Medicine, Ihsan Doğramaci Children's Hospital, Ankara, Turkey.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Blackett PR, Li S, Mulvihill JJ. Ring chromosome 4 in a patient with early onset type 2 diabetes, deafness, and developmental delay. Am J Med Genet A 2005; 137:213-6. [PMID: 16082703 DOI: 10.1002/ajmg.a.20386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To date, most ring formations of chromosome 4 lose distal 4p and usually include the Wolf-Hirschhorn syndrome region [WHS]. We describe a case with r(4) in a girl who presented without features of WHS; she had mild developmental delay, deafness, short stature, obesity, and the onset of type 2 diabetes in adolescence, a distinctive phenotype. Although 4p was significantly deleted on Giemsa banding, the 4p junction was distal to the WHS and FGFR3 but proximal to the D4S3360 marker. The 4q breakpoint was close to the telomere. The phenotype appears different from previous patients with 4p- or r(4), which have had more extensive 4p deletion.
Collapse
Affiliation(s)
- Piers R Blackett
- Section of Diabetes and Endocrinology, Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | | | | |
Collapse
|
11
|
Sigurdardottir S, Goodman BK, Rutberg J, Thomas GH, Jabs EW, Geraghty MT. Clinical, cytogenetic, and fluorescence in situ hybridization findings in two cases of "complete ring" syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 87:384-90. [PMID: 10594875 DOI: 10.1002/(sici)1096-8628(19991222)87:5<384::aid-ajmg3>3.0.co;2-r] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The term "ring syndrome" was proposed to describe a phenotype of growth failure without major malformations due to a ring autosome. The growth failure is thought to be caused by instability of the ring chromosome leading to aneusomy and cell death. Most previous studies of ring chromosomes were based on standard cytogenetic banding techniques and were limited to microscopically detectable deletions in the ring chromosomes. We report on two patients with complete ring (4) and ring (9) chromosomes, respectively. The first was a 15-month-old girl and the second was a 16-month-old boy. They both presented with severe, symmetrical growth failure and normal psychomotor development in the absence of malformations. Their parents had a normal phenotype. The first case had a whorled pattern of hyperpigmentation and hypopigmentation on part of the face and chest, and the second case had a patchy hyperpigmented rash on the trunk. Peripheral blood karyotype of the first patient was 46,XX, r(4)(p16.3q35.2) and of the second 45,XY,-9/46,XY,r(9)(p24q34.3). G-band analysis suggested no loss of material in the ring chromosomes. These findings were confirmed by fluorescence in situ hybridization (FISH) analysis using chromosome-specific subtelomeric probes. The common human telomeric sequences were intact in the first patient but absent in the second patient. The cytogenetic and FISH data in our two cases provide further evidence for the existence of a "complete ring" phenotype independent of the autosome involved. Pigmentary skin changes are a useful clinical sign of mosaicism caused by the ring instability.
Collapse
Affiliation(s)
- S Sigurdardottir
- Kennedy Krieger Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-4922, USA
| | | | | | | | | | | |
Collapse
|