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Li L, Yu Y, Zhang H, Jiang Y, Liu R, Zhang H. Prenatal diagnosis and ultrasonographic findings of partial trisomy of chromosome 6q: A case report and review of the literature. Medicine (Baltimore) 2021; 100:e24091. [PMID: 33466173 PMCID: PMC10545419 DOI: 10.1097/md.0000000000024091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/08/2020] [Accepted: 12/08/2020] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Partial trisomy of the long arm of chromosome 6 syndrome is a rare chromosomal disorder with distinctive phenotypic expressivity, in which cytogenetic abnormalities are usually reported in infancy and childhood. Ultrasonographic findings on trisomy of the distal long arm of chromosome 6 in previous studies are limited. PATIENT CONCERNS A 32-year-old, gravida 6, para 1, pregnant woman who had 4 spontaneous abortions underwent a clinical ultrasound examination at 26 weeks of gestation. DIAGNOSES Ultrasonographic findings were microcephaly, an acoustic image of a transparent septum, a flat nasal bridge, right pulmonary artery stenosis, and a single umbilical artery. Cytogenetic and single-nucleotide polymorphism array analyses were performed to estimate genetic factors of this diagnosis by amniocentesis. INTERVENTIONS After genetic counseling, the patient and her husband opted to terminate the pregnancy. OUTCOMES Cytogenetic examination of the fetus showed the karyotype 46,XX,der(20)t(6;20)(q24;p13). The single-nucleotide polymorphism (SNP) array showed a 22.104-Mb duplication of 6q24.3q27 and a 0.784-Mb deletion of 20p13. LESSONS Ultrasonographic findings of fetal abnormalities, including microcephaly, an acoustic image of a transparent septum, a flat nasal bridge, right pulmonary artery stenosis, and a single umbilical artery, may be related to a 22.104-Mb duplication of 6q24.3q27 and a 0.784-Mb deletion of 20p13. More ultrasonographic and genotype studies are required to extend the phenotypic characterization of partial trisomy 6q syndrome.
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Davies AF, Kirby TL, Docherty Z, Ogilvie CM. Characterization of terminal chromosome anomalies using multisubtelomere FISH. Am J Med Genet A 2003; 120A:483-9. [PMID: 12884426 DOI: 10.1002/ajmg.a.20056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Telomeric repeat sequences (TTAGGG) are known to cap the termini of every human chromosome. Proximal to these repeat sequences are chromosome-specific repeat sequences, which in turn are distal to gene-rich regions. Submicroscopic, subtle, or cryptic abnormalities in these regions can now be investigated using commercial probe sets for all of the chromosome-specific subtelomeric regions of the human genome. Using this technology, previously unidentified genomic imbalance has been found in a proportion of patients with idiopathic developmental delay and learning difficulties. We have used these probe sets to investigate cases with apparently terminal anomalies detected on G-banded chromosome analysis. As a result of such investigations, we have found that 3 (19%) of 16 apparently terminal deletion cases were the result of more complex rearrangements involving other chromosome subtelomeres. The remaining 13 cases contained no chromosome-specific subtelomere repeats on the deleted arm, but in all 16 cases, the TTAGGG telomere repeat cap was present. A further case was investigated where extra material was found in the terminal region of the chromosome 12 short arm, found to represent a complex inversion/duplication/deletion rearrangement. Investigation of all cases with terminal anomalies, including apparently terminal deletions, is likely to uncover further cases involving complex rearrangements and should lead to a greater understanding of the mechanisms by which these abnormalities arise.
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Affiliation(s)
- Angela F Davies
- Cytogenetics Department, Genetics Centre, Guy's & St. Thomas' NHS Trust, London, United Kingdom
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Das S, Lese CM, Song M, Jensen JL, Wells LA, Barnoski BL, Roseberry JA, Camacho JM, Ledbetter DH, Schnur RE. Partial paternal uniparental disomy of chromosome 6 in an infant with neonatal diabetes, macroglossia, and craniofacial abnormalities. Am J Hum Genet 2000; 67:1586-91. [PMID: 11038325 PMCID: PMC1287936 DOI: 10.1086/316897] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2000] [Accepted: 09/27/2000] [Indexed: 11/03/2022] Open
Abstract
Neonatal diabetes, which can be transient or permanent, is defined as hyperglycemia that presents within the first month of life and requires insulin therapy. Transient neonatal diabetes mellitus has been associated with abnormalities of the paternally inherited copy of chromosome 6, including duplications of a portion of the long arm of chromosome 6 and uniparental disomy, implicating overexpression of an imprinted gene in this disorder. To date, all patients with transient neonatal diabetes mellitus and uniparental disomy have had complete paternal isodisomy. We describe a patient with neonatal diabetes, macroglossia, and craniofacial abnormalities, with partial paternal uniparental disomy of chromosome 6 involving the distal portion of 6q, from 6q24-qter. This observation demonstrates that mitotic recombination of chromosome 6 can also give rise to uniparental disomy and neonatal diabetes, a situation similar to that observed in Beckwith-Wiedemann syndrome, another imprinted disorder. This finding has clinical implications, since somatic mosaicism for uniparental disomy of chromosome 6 should also be considered in patients with transient neonatal diabetes mellitus.
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Affiliation(s)
- S Das
- Department of Human Genetics, The University of Chicago, Chicago, IL, 60637, USA.
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Marquis E, Le Monnier de Gouville I, Bouvattier C, Robert JJ, Junien C, Charron D, Hors J, Diatloff-Zito C. HLA-DRB1 and DQB1 genotypes in patients with insulin-dependent neonatal diabetes mellitus. A study of 13 cases. TISSUE ANTIGENS 2000; 56:217-22. [PMID: 11034557 DOI: 10.1034/j.1399-0039.2000.560303.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Insulin-dependent neonatal diabetes mellitus (NDM) is a rare form of diabetes with a heterogeneous genetic background. The HLA-DRB1 and DQB1 genotypes were determined for 13 patients with NDM, from 9 unrelated families. Four patients had permanent NDM (PNDM) and 9 patients had transient NDM (TNDM). No excess of HLA susceptibility markers for type 1 diabetes (IDDM) was observed in this series of patients, whatever the forms of diabetes PNDM or TNDM. Paternal isodisomy of chromosome 6 was observed in two TNDM cases. These observations are consistent with the current hypothesis that there is a recessive susceptibility gene, at least in the transient form of the disease, unlinked to the MHC locus on chromosome 6. Although established in a short series, our results do not support an additive role of IDDM1 in the progression of the disease.
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Affiliation(s)
- E Marquis
- Inserm U383, Université de Paris V, Hôpital Necker-Enfants Malades, Paris, France
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Gardner RJ, Mungall AJ, Dunham I, Barber JC, Shield JP, Temple IK, Robinson DO. Localisation of a gene for transient neonatal diabetes mellitus to an 18.72 cR3000 (approximately 5.4 Mb) interval on chromosome 6q. J Med Genet 1999; 36:192-6. [PMID: 10204843 PMCID: PMC1734332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Transient neonatal diabetes mellitus (TNDM) is a rare condition which presents with intrauterine growth retardation, dehydration, and failure to thrive. The condition spontaneously resolves before 1 year of age but predisposes patients to type 2 diabetes later in life. We have previously shown that, in some cases, TNDM is associated with paternal uniparental disomy (UPD) of chromosome 6 and suggested that an imprinted gene responsible for TNDM lies within a region of chromosome 6q. By analysing three families, two with duplications (family A and patient C) and one with several affected subjects with normal karyotypes (family B), we have further defined the TNDM critical region. In patient A, polymorphic microsatellite repeat analysis identified a duplicated region of chromosome 6, flanked by markers D6S472 and D6S311. This region was identified on the Sanger Centre's chromosome 6 radiation hybrid map (http://www.sanger.ac.uk/HGP/Chr6) and spanned approximately 60 cR3000. Using markers within the region, 418 unique P1 derived artificial chromosomes (PACs) have been isolated and used to localise the distal breakpoints of the two duplications. Linkage analysis of the familial case with a normal karyotype identified a recombination within the critical region. This recombination has been identified on the radiation hybrid map and defines the proximal end of the region of interest. We therefore propose that an imprinted gene for TNDM lies within an 18.72 cR3000 (approximately 5.4 Mb) interval on chromosome 6q24.1-q24.3 between markers D6S1699 and D6S1010.
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Affiliation(s)
- R J Gardner
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Wiltshire, UK
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Abstract
We report on a girl with duplication of 6q22.32 --> qter and microcephaly, frontal bossing, facial anomalies, and webbed neck. She has congenital heart disease, renal hypoplasia, and hearing loss along with severe developmental delay. Published reports of seven other patients are reviewed and compared. The most frequent anomalies include microcephaly, abnormal face, webbed neck, congenital heart disease, limb contractures, and developmental delay.
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Affiliation(s)
- B A Conrad
- Department of Maternal Fetal Medicine, United Hospital, St. Paul, Minnesota, USA
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Henegariu O, Heerema NA, Vance GH. Mild "duplication 6q syndrome": a case with partial trisomy (6)(q23.3q25.3). AMERICAN JOURNAL OF MEDICAL GENETICS 1997; 68:450-4. [PMID: 9021020 DOI: 10.1002/(sici)1096-8628(19970211)68:4<450::aid-ajmg15>3.0.co;2-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report on a female infant with partial 6q trisomy (46,XX,dir dup(6)(q23.3q25.3)) and phenotypic characteristics of the "duplication 6q syndrome," including intrauterine growth retardation, dolichocephaly, depressed nasal bridge, almond-shaped palpebral fissures, short neck, flexion-contractures of the wrists, and mild generalized hypertonia. Although clearly belonging to the described "duplication 6q syndrome," her features were milder than those found in the literature. Comparison of the phenotype of this child with other published reports indicates that specific phenotypic components of the duplication 6q syndrome cannot be attributed to duplication of a specific band or bands on 6q.
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Affiliation(s)
- O Henegariu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis 46202-5251, USA
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Giardino D, Rizzi N, Briscioli V, Bettio D. A de novo 6q11-q15 duplication investigated by chromosome painting. Clin Genet 1994; 46:377-9. [PMID: 7889650 DOI: 10.1111/j.1399-0004.1994.tb04183.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A de novo interstitial duplication of the 6q11-q15 chromosome region, confirmed by the application of a chromosome 6 painting probe, was observed in a patient with craniofacial dysmorphism, psychomotor retardation, cryptorchidism and hypospadias. Despite the publication of several cases showing partial trisomy 6q, to our knowledge the duplication of the proximal region q11-q15 has not previously been reported.
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Affiliation(s)
- D Giardino
- Laboratorio di Citogenetica, Centro Auxologico Italiano, Milan
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Lurie IW. Autosomal imbalance syndromes: genetic interactions and the origin of congenital malformations in aneuploidy syndromes. AMERICAN JOURNAL OF MEDICAL GENETICS 1993; 47:410-6. [PMID: 8135290 DOI: 10.1002/ajmg.1320470323] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In some autosomal imbalance syndromes an additional imbalance interferes with the occurrence of the anomalies typical of the syndrome itself. For example, polydactyly was found in patients with "pure" del(3p) more frequently (11/23) than in patients where these deletions were associated with different partial trisomies (2/28). The opposite situation was shown in del(7q) syndrome where various defects of the holoprosencephalic group were found to be rarer in patients with "pure" deletions, than in cases with simultaneous occurrence of various partial trisomies. It suggests the importance of gene interaction in determining the phenotypic picture of autosomal imbalance syndromes.
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Affiliation(s)
- I W Lurie
- Department of Pediatrics, School of Medicine, University of Maryland at Baltimore
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Uhrich S, FitzSimmons J, Easterling TR, Mack L, Disteche CM. Duplication (6q) syndrome diagnosed in utero. AMERICAN JOURNAL OF MEDICAL GENETICS 1991; 41:282-3. [PMID: 1789280 DOI: 10.1002/ajmg.1320410304] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report on a case of partial duplication 6q detected ultrasonographically. The clinical picture noted in utero is consistent with the adult phenotype previously reported in the literature.
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Affiliation(s)
- S Uhrich
- Department of Obstetrics and Gynecology, University of Washington, Seattle
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Pivnick EK, Qumsiyeh MB, Tharapel AT, Summitt JB, Wilroy RS. Partial duplication of the long arm of chromosome 6: a clinically recognisable syndrome. J Med Genet 1990; 27:523-6. [PMID: 2213846 PMCID: PMC1017204 DOI: 10.1136/jmg.27.8.523] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Reciprocal translocations involving the short arm of acrocentric chromosomes can segregate to produce partial duplications without associated deletions. We present a case of an infant with a 46,XY,-15,+der(15),T(6;15)(q23;p12)pat chromosome complement. The infant had multiple congenital abnormalities including cranial anomalies, facial dysmorphism, anterior webbing of the neck, cardiac anomalies, and joint contractures. From a comparison of the infant's phenotype with 20 other patients with a similar duplication, it is evident that partial duplication of the long arm of chromosome 6 is a clinically diagnosable syndrome.
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Affiliation(s)
- E K Pivnick
- Department of Pediatrics, University of Tennessee, Memphis 38163
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Shen-Schwarz S, Hill LM, Surti U, Marchese S. Deletion of terminal portion of 6q: report of a case with unusual malformations. AMERICAN JOURNAL OF MEDICAL GENETICS 1989; 32:81-6. [PMID: 2705486 DOI: 10.1002/ajmg.1320320117] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We present the necropsy findings of a 21-week-gestation male fetus with deletion of the terminal portion of long arm of chromosome 6 [46,XY,del(6)(q23----qter)]. Major anomalies include intrauterine growth retardation, facial anomalies, nuchal cyst, scoliosis, bilateral diaphragmatic hernias, persistent common atrioventricular canal, absent olfactory bulbs and agenesis of corpus callosum. In aberrations of chromosome 6q, patients usually have psychomotor retardation, somatic growth failure, and facial anomalies; nuchal cyst and bilateral diaphragmatic hernias have not yet been described.
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Affiliation(s)
- S Shen-Schwarz
- Department of Pathology, Magee-Womens Hospital, Pittsburgh, Pennsylvania
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