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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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Srebniak MI, van Zutven LJCM, Petit F, Bouquillon S, van Heel IPJ, Knapen MFCM, Cornette JMJ, Kremer A, Van Opstal D, Diderich KEM. Interstitial 6q21q23 duplication - variant of variable phenotype and incomplete penetrance or benign duplication? Mol Cytogenet 2016; 9:43. [PMID: 27274769 PMCID: PMC4891832 DOI: 10.1186/s13039-016-0253-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/24/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chromosome 6q duplication syndrome is a chromosome abnormality associated with characteristic phenotypic features such as intellectual disability (ID), short stature, feeding difficulties, microcephaly, dysmorphic features (prominent forehead, downslanting palpebral fissures, flat nasal bridge, tented upper lip, micrognathia, short webbed neck) and joint contractures. Only a few cases of pure partial 6q trisomy have been published and the severity of the phenotype seems to depend on the breakpoint position. Unfortunately, most of these cases were identified using karyotyping or FISH, so breakpoints at the molecular level and thus gene content are not known. CASES PRESENTATION We report the first two families with an interstitial 6q duplication identified by karyotyping where the gene content and breakpoints were characterized with microarray. In family 1, the 6q22.1q23.2 duplication was detected in a female patient with ID. In family 2, the 6q21q22.33 duplication was identified in a male fetus with multiple congenital malformations. In both families, the duplication seems to show phenotypic heterogeneity and in family 1 also incomplete penetrance suggesting the co-existence of an "additional hit" in affected patients. This "additional hit" was identified in the first family to be a microduplication in 16p11.2, a known susceptibility locus (SL) for neurodevelopmental disorders, that co-segregated with an abnormal phenotype in the affected family members. CONCLUSIONS Our study shows that interstitial 6q21q23 duplication may represent a private variant that is benign, but may also contribute to developmental disorders of variable expressivity in a "multi-hit" model. Finding the "additional hit" within the family is therefore very important for genetic counseling and assessment of the CNV penetrance within the particular family.
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Affiliation(s)
- Malgorzata I Srebniak
- Department of Clinical Genetics, Erasmus MC, Ee2475, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Laura J C M van Zutven
- Department of Clinical Genetics, Erasmus MC, Ee2475, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Florence Petit
- Department of Clinical Genetics, University Hospital, Lille, France
| | | | - Ilse P J van Heel
- Department of Clinical Genetics, Erasmus MC, Ee2475, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Maarten F C M Knapen
- Department of Obstetrics and Gynecology, subdivision Obstetrics and Prenatal Medicine, Erasmus MC, Rotterdam, The Netherlands ; Stichting Prenatale Screening Zuidwest Nederland, Wytemaweg 80, Na-1509, 3015, GE Na-1503 Rotterdam, The Netherlands
| | - Jerome M J Cornette
- Department of Obstetrics and Gynecology, subdivision Obstetrics and Prenatal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Andreas Kremer
- Department of Bioinformatics Erasmus MC, Rotterdam, The Netherlands
| | - Diane Van Opstal
- Department of Clinical Genetics, Erasmus MC, Ee2475, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Karin E M Diderich
- Department of Clinical Genetics, Erasmus MC, Ee2475, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
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Tabet AC, Aboura A, Gérard M, Pilorge M, Dupont C, Gadisseux JF, Hervy N, Pipiras E, Delahaye A, Kanafani S, Verloes A, Benzacken B, Betancur C. Molecular characterization of a de novo 6q24.2q25.3 duplication interrupting UTRN in a patient with arthrogryposis. Am J Med Genet A 2010; 152A:1781-8. [PMID: 20583184 DOI: 10.1002/ajmg.a.33433] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Chromosome 6q duplications have been documented repeatedly, allowing the delineation of a "6q duplication syndrome," characterized by hypertelorism, downslanting palpebral fissures, tented upper lip, short neck, severe mental and growth retardation, and joint contractures. Most reported cases result from malsegregation of a reciprocal translocation leading to a terminal 6q duplication and partial monosomy of another chromosome. Only 11 cases of de novo pure duplication have been reported so far. The breakpoints do not appear to be recurrent, but in most cases they have not been characterized molecularly, precluding genotype-phenotype correlation. We report on an 8-year-old girl with a phenotype consistent with mild 6q duplication syndrome, including characteristic physical findings, mild mental retardation, and joint contractures. She carries a 13 Mb de novo 6q24.2q25.3 duplication, diagnosed by high-resolution karyotype and confirmed by array-CGH. Molecular characterization of the duplicated segment with quantitative PCR showed that the proximal breakpoint is localized within the UTRN gene, encoding utrophin, the autosomal homologue of dystrophin. We discuss the possible implication of UTRN in arthrogryposis associated with duplications spanning the 6q23q26 region.
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Affiliation(s)
- Anne-Claude Tabet
- AP-HP, Cytogenetics Unit, Department of Genetics, Robert Debré Hospital, Paris, France.
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Valerio D, Di Domenico A, Felicetti M, La Boccetta A, Ferrara C, Antonio N, Borrelli AL. Prenatal diagnosis of a partial 6q trisomy: a case report. Prenat Diagn 2006; 26:917-9. [PMID: 16845680 DOI: 10.1002/pd.1526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To present a case of partial 6q trisomy diagnosed prenatally. METHOD A 28-year-old woman underwent genetic amniocentesis at 23 weeks of gestation on the detection of an enlarged nuchal fold (8.5 mm), which was the only clinical abnormality on routine ultrasound examination. Fetal karyotyping revealed a partial trisomy 6q (q21-q22) caused by a balanced maternal chromosomal insertion. RESULTS A female infant was delivered at 38 weeks of gestation. At birth, minor dysmorphisms were recorded, which included low set ears, macrocephaly and a webbed neck. At 17 months of age, neurological developmental assessment was normal. CONCLUSIONS The appearance of phenotypic expression and clinical outcome of partial 6q trisomy depends on the specific chromosomal region involved in the segmental aneusomy.
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Affiliation(s)
- Domenico Valerio
- Laboratorio di Diagnosi Prenatale, Istituto di Ricerche Genetiche--Napoli, Italy.
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Seel C, Hager HD, Jauch A, Tariverdian G, Zschocke J. Survival up to age 10 years in a patient with partial duplication 6q: case report and review of the literature. Clin Dysmorphol 2005. [DOI: 10.1097/00019605-200501000-00013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Grati FR, Lalatta F, Turolla L, Cavallari U, Gentilin B, Rossella F, Cetin I, Antonazzo P, Bellotti M, Dulcetti F, Baldo D, Tenconi R, Simoni G, Miozzo M. Three cases with de novo 6q imbalance and variable prenatal phenotype. Am J Med Genet A 2005; 136:254-8. [PMID: 15957159 DOI: 10.1002/ajmg.a.30837] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe two families in which three fetuses had a de novo 6q imbalance and abnormal phenotypes. We determined the boundaries and the parental origin of the chromosomal alterations by segregation analysis using a panel of short tandem repeats (STRs) located on 6q. Cases 1 and 2 (family A) were two sibs with 6q imbalance involving different regions. Case 1 was a female fetus with arthrogryposis, who had a complex rearrangement resulting in two deleted regions (6q22 and 6q25.1-q25.2) and a duplication of 6q23-q25.1. This latter imbalance was reported previously and is associated with joint contractures and short neck, also present in this fetus. The sib (case 2) had intrauterine growth restriction (IUGR) and agenesis of the ductus venosus. This male died shortly after birth; postnatal karyotype and molecular investigations showed a 6q21 de novo deletion. Case 3 (family B) had a prenatally detected deletion of 6q14-q16. Autopsy of the fetus documented minor facial anomalies and contractures of the limbs. All rearrangements were de novo and of paternal origin. Our data and the consistent number of cases of de novo 6q alterations previously reported suggest that chromosome arm 6q could be prone to rearrangements resulting in heterogeneous phenotypes. In family A, chromosome 6q imbalances involving different chromosomal regions were present in two consecutive pregnancies. In such cases counseling should suggest the impossibility of excluding recurrence of a chromosomal imbalance, and should discuss the option of early prenatal diagnosis in subsequent pregnancies.
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Affiliation(s)
- Francesca R Grati
- Dipartimento di Medicina, Chirurgia ed Odontoiatria, Genetica Medica, Università degli Studi di Milano, Milano, Italia
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Cavani S, Perfumo C, Faravelli F, Malacarne M, Sogliani M, Piombo G, Zerega G, Zucca M, Dagna Bricarelli F, Pierluigi M. Cryptic 1p36.3/6q25.2 translocation in three generations ascertained through a foetus with IUGR and cerebral malformations. Prenat Diagn 2003; 23:819-23. [PMID: 14558026 DOI: 10.1002/pd.678] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Here we describe a foetus with intrauterine growth retardation (IUGR), cerebral malformations and a 46,XY,der(1),t(1;6)(p36.3;q25.2) karyotype owing to a familial cryptic translocation segregating in three generations. A balanced translocation was present in the mother, the maternal uncle, the aunt and the grandmother. A female first cousin with dysmorphisms, hydrocephalus and mental retardation was a carrier of a partial trisomy 1p and a partial monosomy 6q. Multiple miscarriages were present in the family pedigree. Parents of the foetus had three other pregnancies: a male with a balanced translocation, and two foetuses with 1p36.3-pter monosomy and 6q25.2-qter trisomy.
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MESH Headings
- Abnormalities, Multiple/diagnosis
- Abnormalities, Multiple/embryology
- Abnormalities, Multiple/genetics
- Adult
- Chromosomes, Human, Pair 1
- Chromosomes, Human, Pair 6
- Diagnosis, Differential
- Family
- Fatal Outcome
- Female
- Fetal Growth Retardation/complications
- Fetal Growth Retardation/diagnosis
- Genetic Counseling
- Humans
- Infant, Newborn
- Male
- Pedigree
- Pregnancy
- Pregnancy Trimester, Third
- Prenatal Diagnosis
- Telencephalon/abnormalities
- Translocation, Genetic
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Affiliation(s)
- S Cavani
- Laboratorio di Genetica Umana, EO Ospedali Galliera, Genova, Italy
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Abstract
We report on two patients with rare 6q duplications. The karyotype of patient 1 is 46,XY,dup(6)(q21q23.3). The karyotype of patient 2 is 46,XX,dup(6)(q21.15q23.3). These two patients have some nonspecific physical findings in common including a depressed nasal bridge, epicanthal folds, mild heart defects, and developmental delay, but each had other congenital anomalies.
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Affiliation(s)
- V M Pratt
- Medical Genetics and Birth Defects Center, Henry Ford Hospital, Detroit, Michigan, USA
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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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Kulharya AS, Carlin ME, Stettler RW, Huslig M, Kukolich MK, Garcia-Heras J, Stettler WA. Prenatal diagnosis of a de novo trisomy 6q22.2-->6qter and monosomy 1pter-->1p36.3. Case report with a 2-year follow-up and a brief review of other prenatal cases of partial trisomy 6q. Clin Genet 1997; 51:115-7. [PMID: 9111999 DOI: 10.1111/j.1399-0004.1997.tb02431.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report a de novo trisom 6q22.2-->6qter and monosomy 1pter-->1p36.3 identified in amniocytes by GTG banding and FISH. While ultrasonography demonstrated malformations that did not suggest a specific chromosomal syndrome, a male infant with features consistent with trisomy 6q was born. He was followed up until 23 months, when he died after cardiac surgery. The only two other prenatal cases of trisomy 6q were compared with our patient. A literature review showed that trisomy 6q has not been reported in association with the anomalies seen by ultrasound in this case.
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Affiliation(s)
- A S Kulharya
- Division of Medical Genetics, Medical College of Georgia, Augusta 30912-3720, 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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