scholarly journals Clinical Expression of an Inherited Unbalanced Translocation in Chromosome 6

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Bani Bandana Ganguly ◽  
Vijay Kadam ◽  
Nitin N. Kadam

Unbalanced chromosomal rearrangements are not common; however, they have a significant clinical expression. The parental balanced translocation produces unbalanced chromosome, which is transmitted to next generation through fertilization of gametes carrying the derivative chromosome. The carriers of balanced rearrangements mostly do not have recognizable phenotypic expression. We report a family comprising of healthy and non-consanguineous young parents and their preemie newborn severely affected with congenital anomalies and systemic disorders. Conventional Gbanding analysis of somatic chromosomes identified a balanced translocation, t(6;10)(p23;q24), in mother and an unbalanced rearrangement, der(6)t(6:10)(p23;q24)mat, in the child. The child has inherited a derivative chromosome 6 with partial deletion of 6(p23-pter) and partial trisomy 10(q24-qter), which has resulted in fusion of genes of two different chromosomes. The prominent phenotypic features of del(6p), including high forehead, flat nasal bridge, agenesis of left ear, atrial septal defect (ASD), craniosynostosis, and growth retardation, are overlapping with specific Axenfeld-Reiger-, Larsen-, and Ritscher-Sinzel/3-C syndromes, however, lacking in ocular anomalies, skeletal laxity, or cerebellar malformation. Therefore, this paper rules out the isolated effect of del(6p23) or trisomy 10(q24) on distinct previously reported syndromes and proposes the combined effect of unbalanced chromosomal alteration.

Author(s):  
Anjali Satyen Sabnis ◽  
Anurita S Pais ◽  
Gauri Pradhan

Chromosomal analysis is practiced routinely since long time in congenital malformations to find out structural and or numerical chromosomal aberrations. Translocation is one of the structural chromosomal aberrations where exchange of genetic material between the chromosomes is seen because of two breakpoints. On the basis of involvement of type of chromosome, two different types of translocation are defined. A case of two-year-old girl child with the history of developmental delay, generalised hypotonia and recurrent infections was reported whose cytogenetic analysis showed additional genetic material on ‘p’ arm of one chromosome 6. To find out the additional genetic material, parental chromosomal study was done which revealed balanced translocation between ‘q’ arm of chromosome 10 and ‘p’ arm of chromosome 6 and normal chromosomal pattern in father. Balanced translocation in mother gave rise to formation of derivative chromosome 6 which was transmitted to daughter causing partial trisomy of 10q and partial monosomy of 6p. This gain and loss of genetic material could be the cause of phenotypic features. In the current case, karyotyping was an investigation of choice and offering genetic counselling regarding prenatal diagnosis in future pregnancy was a thoughtful step.


2020 ◽  
Vol 77 (7) ◽  
pp. 754-757
Author(s):  
Ivana Joksic ◽  
Thomas Liehr ◽  
Mina Toljic ◽  
Natasa Karadzov-Orlic ◽  
Zagorka Milovanovic ◽  
...  

Introduction. Partial trisomy of chromosome 12 long arm is rare condition with significant clinical impact and is usually diagnosed postnatally. Case report. We present prenatal sonographic findings and molecular cytogenetic characterization of partial trisomy 12q and partial monosomy 2q in two consecutive pregnancies of a healthy non-consanguineous couple. A 35-year-old pregnant woman G3P1A1 was referred to genetic counseling due to sonographic anomalies detected in the fetus. First trimester ultrasound examination revealed hyperechogenic focus in the left cardiac ventricle, single umbilical artery, hyperechogenic bowel and unilateral clubfoot with knee joint ankylosis. Previous pregnancy of the couple was terminated at 26th gestation weeks due to multiple fetal anomalies: bilateral ventriculomegaly, corpus callosum hypoplasia, single umbilical artery and clubfoot. In G3P1A1, amniocentesis was performed and cytogenetic analyses revealed a derivative chromosome 2. Subsequent cytogenetic analyses of parental lymphocytes showed that paternal karyotype was normal, while maternal karyotype showed a der(2). Metaphase fluorescence in situ hybridization (FISH) studies demonstrated partial trisomy 12q24.2?12qter and partial monosomy 2q37.3?2qter in the fetus, resulting from an unbalanced segregation of a maternal balanced translocation t(2;12)(q37.3;q24.2). To date, this is the first such prenatally detected case. Literature search revealed three more cases of prenatally detected partial trisomy 12q and anomalies described were consistent with ones detected in present case. Our findings contribute to further clinical delineation of partial trisomy 12q. Conclusion. Prenatal detection of single umbilical artery, clubfoot, arthogryposis and ventriculomegaly should alert suspicion to chromosome 12q aberrations.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Natalya A. Lemskaya ◽  
Svetlana A. Romanenko ◽  
Mariia A. Rezakova ◽  
Elena A. Filimonova ◽  
Dmitry Yu. Prokopov ◽  
...  

Abstract Background There are many reports on rearrangements occurring separately in the regions of chromosomes 9p and 15q affected in the case under study. 15q duplication syndrome is caused by the presence of at least one extra maternally derived copy of the Prader–Willi/Angelman critical region. Trisomy 9p is the fourth most frequent chromosome anomaly with a clinically recognizable syndrome often accompanied by intellectual disability. Here we report a new case of a patient with maternally derived unique complex sSMC resulting in partial trisomy of both chromosomes 9 and 15 associated with intellectual disability. Case presentation We characterise a supernumerary derivative chromosome 15: 47,XY,+der(15)t(9;15)(p21.2;q13.2), likely resulting from 3:1 malsegregation during maternal gametogenesis. Chromosomal analysis showed that a phenotypically normal mother is a carrier of balanced translocation t(9;15)(p21.1;q13.2). Her 7-year-old son showed signs of intellectual disability and a number of physical abnormalities including bilateral cryptorchidism and congenital megaureter. The child’s magnetic resonance imaging showed changes in brain volume and in structural and functional connectivity revealing phenotypic changes caused by the presence of the extra chromosome material, whereas the mother’s brain MRI was normal. Sequence analyses of the microdissected der(15) chromosome detected two breakpoint regions: HSA9:25,928,021-26,157,441 (9p21.2 band) and HSA15:30,552,104-30,765,905 (15q13.2 band). The breakpoint region on chromosome HSA9 is poor in genetic features with several areas of high homology with the breakpoint region on chromosome 15. The breakpoint region on HSA15 is located in the area of a large segmental duplication. Conclusions We discuss the case of these phenotypic and brain MRI features in light of reported signatures for 9p partial trisomy and 15 duplication syndromes and analyze how the genomic characteristics of the found breakpoint regions have contributed to the origin of the derivative chromosome. We recommend MRI for all patients with a developmental delay, especially in cases with identified rearrangements, to accumulate more information on brain phenotypes related to chromosomal syndromes.


2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Hannie Kartapradja ◽  
Nanis Sacharina Marzuki ◽  
Mark D. Pertile ◽  
David Francis ◽  
Lita Putri Suciati ◽  
...  

We report an exceptional complex chromosomal rearrangement (CCR) found in three individuals in a family that involves 4 chromosomes with 5 breakpoints. The CCR was ascertained in a phenotypically abnormal newborn with additional chromosomal material on the short arm of chromosome 4. Maternal karyotyping indicated that the mother carried an apparently balanced CCR involving chromosomes 4, 6, 11, and 18. Maternal transmission of the derivative chromosome 4 resulted in partial trisomy for chromosomes 6q and 18q and a partial monosomy of chromosome 4p in the proband. Further family studies found that the maternal grandmother carried the same apparently balanced CCR as the proband’s mother, which was confirmed using the whole chromosome painting (WCP) FISH. High resolution whole genome microarray analysis of DNA from the proband’s mother found no evidence for copy number imbalance in the vicinity of the CCR translocation breakpoints, or elsewhere in the genome, providing evidence that the mother’s and grandmother’s CCRs were balanced at a molecular level. This structural rearrangement can be categorized as an exceptional CCR due to its complexity and is a rare example of an exceptional CCR being transmitted in balanced and/or unbalanced form across three generations.


2015 ◽  
Vol 146 (3) ◽  
pp. 222-229 ◽  
Author(s):  
Alessandra Iannuzzi ◽  
Viviana Genualdo ◽  
Angela Perucatti ◽  
Alfredo Pauciullo ◽  
Giovanna Varricchio ◽  
...  

A newborn calf of the Agerolese cattle breed underwent clinical cytogenetic investigation because of hyperflexion of the forelimbs, red eyes and the inability to stand. Anamnesis revealed that the mother, phenotypically normal, carried a chromosomal aberration. The newborn died after 2 weeks, and no remarkable alterations were found by the veterinarian on postmortem examination. The mother was a carrier of a reciprocal balanced translocation rcp(11;25)(q11,q14∼21) detected after a cytogenetic investigation in 2011; however, the analysis of the newborn revealed a different chromosomal aberration with partial trisomy of chromosome 25 and partial monosomy of chromosome 11. In fact, the results showed both chromosomes 25, one chromosome 11 and only one long derivative chromosome (der11). FISH analysis, performed using BAC clones, confirmed the chromosomes and their regions involved. Finally, both the localization of the breakpoints on band q11 (centromere) of chromosome 11 and band q14-21 of chromosome 25, and the complete loss of the der25 identified the aberration as an unbalanced translocation 60,XX,der(11)t(11;25)(q11;q14∼21). A comparison with human chromosomes was also performed to search for similarities and possible genes involved in order to study their effects, thus extending the knowledge of these aberrations by case reports.


2017 ◽  
Vol 06 (03) ◽  
pp. 165-168 ◽  
Author(s):  
Luis Mendez-Rosado ◽  
Araceli Lantigua ◽  
Juan Galarza ◽  
Ahmed Hamid Al-Rikabi ◽  
Monika Ziegler ◽  
...  

AbstractGain of copy numbers can be due to different chromosomal rearrangements such as direct or indirect duplications, translocations, small supernumerary marker chromosomes, or insertions. In a 3-year-old boy with dysmorphic features and developmental delay, chromosome analyses revealed a derivative chromosome 5. Microdissection and reverse fluorescence in situ hybridization identified the in 5p13.1 inserted part as 17p12-p11.2 material. Thus the patient suffered from a rare combination of genomic disorder, that is, Charcot-Marie-Tooth disease type 1A and Potocki-Lupski syndrome. Parental studies indicated that the abnormality was de novo in origin. As the question how this rearrangement arose cannot be answered conclusively, formal genetic counseling is warranted, which includes a discussion regarding the possibility of gonadal mosaicism. In conclusion, this case highlights that chromosome 17p is genetically relatively instable, and thus it can lead to rare chromosomal conditions.


2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Sabrina C. Burn ◽  
Kali Swift ◽  
Maria Palmquist

The occurrence of simultaneous de novo chromosomal aberrations is extremely rare. Here, we describe two, previously unreported, simultaneous de novo interstitial duplications of chromosomes 7p and 15q. Amniocentesis was completed for a healthy gravida 4 para 3 woman due to her advanced maternal age and concurrent ultrasound findings of partial vermian agenesis, choroid-plexus cysts, and hypoplastic nasal bone. Cytogenetic analysis of cultured amniocytes by conventional chromosome analysis, comparative genomic hybridization, and fluorescence in situ hybridization revealed two interstitial duplications of the chromosomal regions 7p22.1p21.1 and 15q24.1, leading to partial trisomy of 7p and 15q and karyotype 46,XY,dup(7)(p22.1-p21.1),dup (15)(q24.1). Parental chromosomal analysis did not identify any heritable changes, suggesting both mutations were de novo in nature. Postnatal examination of the neonate was significant for low set ears, thick helices, flat nasal bridge, ankyloglossia, and aberrant head shape and size concerning for craniosynostosis. Postnatal MRI was consistent with Dandy-Walker variant showing hypogenesis of the inferior cerebellar vermis. To our knowledge, there are no prenatal or postnatal reports of comparable duplications involving these two regions simultaneously. Continued observation of the neonate may reveal further phenotypic consequences of these two simultaneous de novo interstitial duplications.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Abreu-González ◽  
C. García-Delgado ◽  
A. Cervantes ◽  
A. Aparicio-Onofre ◽  
R. Guevara-Yáñez ◽  
...  

Chromosomal abnormalities that result in genomic imbalances are a major cause of congenital and developmental anomalies. Partial duplication of chromosome 3q syndrome is a well-described condition, and the phenotypic manifestations include a characteristic facies, microcephaly, hirsutism, synophrys, broad nasal bridge, congenital heart disease, genitourinary disorders, and mental retardation. Approximately 60%–75% of cases are derived from a balanced translocation. We describe a family with a pure typical partial trisomy 3q syndrome derived from a maternal balanced translocation t(3;13)(q26.2;p11.2). As the chromosomal rearrangement involves the short arm of an acrocentric chromosome, the phenotype corresponds to a pure trisomy 3q26.2-qter syndrome. There are 4 affected individuals and several carriers among three generations. The report of this family is relevant because there are few cases of pure duplication 3q syndrome reported, and the cases described here contribute to define the phenotype associated with the syndrome. Furthermore, we confirmed that the survival until adulthood is possible. This report also identified the presence of glycosaminoglycans in urine in this family, not related to the chromosomal abnormality or the phenotype.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Marcelo Razera Baruffi ◽  
Deise Helena de Souza ◽  
Rosana Aparecida Bicudo da Silva ◽  
Ester Silveira Ramos ◽  
Danilo Moretti-Ferreira

Balanced X-autosome translocations are rare, and female carriers are a clinically heterogeneous group of patients, with phenotypically normal women, history of recurrent miscarriage, gonadal dysfunction, X-linked disorders or congenital abnormalities, and/or developmental delay. We investigated a patient with ade novoX;19 translocation. The six-year-old girl has been evaluated due to hyperactivity, social interaction impairment, stereotypic and repetitive use of language with echolalia, failure to follow parents/caretakers orders, inconsolable outbursts, and persistent preoccupation with parts of objects. The girl has normal cognitive function. Her measurements are within normal range, and no other abnormalities were found during physical, neurological, or dysmorphological examinations. Conventional cytogenetic analysis showed ade novobalanced translocation, with the karyotype 46,X,t(X;19)(p21.2;q13.4). Replication banding showed a clear preference for inactivation of the normal X chromosome. The translocation was confirmed by FISH and Spectral Karyotyping (SKY). Although abnormal phenotypes associated withde novobalanced chromosomal rearrangements may be the result of disruption of a gene at one of the breakpoints, submicroscopic deletion or duplication, or a position effect, X; autosomal translocations are associated with additional unique risk factors including X-linked disorders, functional autosomal monosomy, or functional X chromosome disomy resulting from the complex X-inactivation process.


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