scholarly journals Prenatal Diagnosis of Rare Familial Unbalanced Translocation of Chromosomes 7 and 12

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Berrin Tezcan ◽  
Foteini Emmanouella Bredaki

Case Details. We report rare familial unbalanced translocation of chromosomes 7 and 12, which was diagnosed prenatally at 20+3 weeks of gestation. Woman’s partner had been tested in the past and was found to be a carrier of a balanced translocation; his karyotype showed a balanced reciprocal translocation of 46, XY, t(7;12)(q34;q24,32). Partner’s brother had an unbalanced form of the translocation with severe learning disability. The diagnosis of the anomaly was based on two- and three-dimensional ultrasound and microarray analysis. Ultrasonography findings included fetal microcephaly and alobar holoprosencephaly, dysmorphic face (flat occiput, absent nasal bone, microphthalmia, hypotelorism, and single nostril), and hyperechogenic bowel. Genome-wide array analysis and cytogenetic results from the amniotic fluid showed unbalanced translocation in chromosomes 7 and 12 with deletion of an approximately 16.5 Mb and a duplication of 6.1 Mb, respectively, Arr 7q34q36.3(142,668,576-159,161,648)x1,12q24.32q24.33(127,708,720-133,777,560)x3, karyotype (der (7) t(7;12) (q34;q24)pat). This unbalanced translocation was due to the segregation of the father’s balanced translocation. In this particular case, the recurrence of an unbalanced translocation in the subsequent pregnancies is estimated to be 20%. Understanding the individuals’ phenotype in association with the gain and loss of copy number is important and can further provide us with information on that particular region of the named chromosomes.

1992 ◽  
Vol 13 (9) ◽  
pp. 334-342
Author(s):  
John H. DiLiberti ◽  
Mark A. Greenstein ◽  
Sally Shulman Rosengren

The enormous progress witnessed in the field of prenatal diagnosis during the past two decades is likely to continue into the future. Improved imaging techniques are likely to enhance the resolution of noninvasively obtained fetal images considerably over their current excellent quality. Although this undoubtedly will be true for ultrasonography, the increased speed of magnetic resonance equipment may offer a new realm of imaging possibilities. Computerized image processing, analysis, and three-dimensional reconstructions all should make interpretation of fetal images easier and more understandable to the nonspecialist. Advances in molecular genetics will continue to accelerate, greatly expanding the range and accuracy of prenatal diagnosis. The alert pediatrician who is sensitive to genetic issues may, by early detection of pediatric disorders and careful family history assessment, be in a position to identify families at risk for serious genetic conditions and provide the opportunity to make informed decisions on reproductive options that avert a major tragedy. The pediatrician, working with obstetric colleagues, should be part of a team effort to support families going through prenatal testing. Familiarity with these rapidly changing technologies will make it far easier to support the family needing additional explanation about prenatal diagnosis issues.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1061-1061
Author(s):  
Laura Mosca ◽  
Sonia Fabris ◽  
Giovanna Cutrona ◽  
Luca Agnelli ◽  
Serena Matis ◽  
...  

Abstract B-cell chronic lymphocytic leukemia (B-CLL) is a genetically heterogeneous disease with a variable clinical course. Chromosomal changes have been identified by FISH in approximately 80% of patients, and the presence of specific lesions, such as trisomy 12 and 13q14, 11q23, 17p13.1 and 6q23 deletions represent prognostic markers for disease progression and survival. In order to characterize further the complexity of B-CLL genomic lesions, we performed high density, single nucleotide polymorphism (SNP) array analysis in highly purified neoplastic cells (>92%) from a panel of 100 untreated, newly diagnosed patients (57 males and 43 females; age, median 63 years, range 30–87) in Binet stage A. All patients were investigated by FISH for the presence of trisomy 12 (21 cases); 13q14 deletion (44 cases, 34 as the sole abnormality); 11q22.3, 17p13.1 and 6q23 (15, 7 and 2 patients, respectively). In addition, ZAP-70 and CD38 expression resulted positive in 42 and 46 patients, whereas IgVH genes were mutated in 45 patients. Genome-wide DNA profiling data were generated on GeneChip® Human Mapping 250K NspI arrays (Affymetrix); copy number alterations (CNA) were calculated using the DNA copy Bioconductor package, which looks for optimal breakpoints using circular binary segmentation (CBS) (Olshen et al, 2004). A total of 782 CNAs (ranging from 1 to 31 per sample, mean and median values 7.82 and 7, respectively) were detected; DNA losses (365/782=46.67% loss; 194/782=24.81% biallelic deletion) were found to be more frequent than gains (148/782=18.93% gain; 75/782=9.59% amplification). The most recurrent alterations detected by FISH were all confirmed by SNP array analysis, strengthening further the good reliability of such high-resolution technology. We identified 12 minimally altered regions (MARs) larger than 100 kb with a frequency higher than 5%. Among well known alterations, the largest was represented by chromosome 12 trisomy, followed by 6q, 17p and 11q23 deletions (32.87, 19.09 and 10.43 Mb, respectively) and 13q14 deletion (635 kb). Gain of 2p25.3 involves a common region of 4.39 Mb region in 7 patients, although it was extended to the whole short arm of chromosome 2 in 3 cases. Among those alterations previously described in B-CLL, we found losses at 14q32.33 (12 pts) and 22q11.2 (5 pts) involving the IGH and IGLλ loci, respectively. With regard to novel regions, we identified losses at 4q35.2 (5 pts) and 11q25 (6 pts). In addition we found a high frequency of losses/gains at 14q11.2 (42 pts) and 15q11.2 (33 pts), two genomic regions reported to be affected by DNA copy number variations in normal individuals. As regards correlations between CNAs and biological markers, we found that the number of CNAs is significantly higher in cases with unmutated IgVH (9.4; range 2–31) as compared with mutated IgVH (6; range 1–13) (p=0.002), while neither CD38 nor ZAP-70 expression showed significant correlation. In addition, a significant higher number of either CNAs (p=0.001), total MARs (p<0.0001) or even only novel MARs (p=0.009) was significantly associated with cases with 17p deletion or multiple cytogenetic aberrations as evaluated by FISH analysis. Our data indicate that genetic abnormalities involving chromosomal gains and losses are very common in early-stage B-CLL and further support the application of high resolution SNP array platforms in the characterization of genetic changes in the disease. In addition, we detected novel altered chromosomal regions that warrant further investigations to better define their pathogenetic and prognostic role in B-CLL.


2021 ◽  
Vol 12 ◽  
Author(s):  
Meiying Cai ◽  
Xianguo Fu ◽  
Liangpu Xu ◽  
Na Lin ◽  
Hailong Huang

Smith-Magenis syndrome and Potocki-Lupski syndrome are rare autosomal dominant diseases. Although clinical phenotypes of adults and children have been reported, fetal ultrasonic phenotypes are rarely reported. A retrospective analysis of 6,200 pregnant women who received invasive prenatal diagnosis at Fujian Provincial Maternal and Child Health Hospital between October 2016 and January 2021 was performed. Amniotic fluid or umbilical cord blood was extracted for karyotyping and single nucleotide polymorphism array analysis. Single nucleotide polymorphism array analysis revealed six fetuses with copy number variant changes in the 17p11.2 region. Among them, one had a copy number variant microdeletion in the 17p11.2 region, which was pathogenically analyzed and diagnosed as Smith-Magenis syndrome. Five fetuses had copy number variant microduplications in the 17p11.2 region, which were pathogenically analyzed and diagnosed as Potocki-Lupski syndrome. The prenatal ultrasound phenotypes of the six fetuses were varied. The parents of two fetuses with Potocki-Lupski syndrome refused verification. Smith-Magenis syndrome in one fetus and Potocki-Lupski in another were confirmed as de novo. Potocki-Lupski syndrome in two fetuses was confirmed to be from maternal inheritance. The prenatal ultrasound phenotypes of Smith-Magenis syndrome and Potocki-Lupski syndrome in fetuses vary; single nucleotide polymorphism array analysis is a powerful diagnostic tool for these diseases. The ultrasonic phenotypes of these cases may enrich the clinical database.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Ingrid Schwach Werneck Britto ◽  
Sandra Regina Silva Herbest ◽  
Giselle Darahem Tedesco ◽  
Carolina Leite Drummond ◽  
Luiz Claudio Silva Bussamra ◽  
...  

We report on a prenatal diagnosis of ring chromosome 15 in a fetus with left congenital diaphragmatic hernia (CDH) and severe intrauterine growth restriction (IUGR). A 31-year-old woman, gravida 2 para 1, was referred because of increased nuchal translucency at gestational age of 13 weeks. Comprehensive fetal ultrasound examination was performed at 19 weeks revealing an early onset IUGR, left CDH with liver herniation, and hypoplastic nasal bone. Three-dimensional ultrasound (rendering mode) showed low set ears and depressed nasal bridge. Amniocentesis was performed with a result of a 46,XX,r(15) fetus after a cytogenetic study. A 1,430 g infant (less than third percentile) was born at 36 weeks. The infant presented with respiratory failure and died at 2 h of life. Postnatal karyotype from the umbilical cord confirmed the diagnosis of 15-ring chromosome. We described the main prenatal 2D- and 3D-ultrasound findings associated with ring chromosome 15. The interest in reporting the present case is that CDH can be associated with the diagnosis of 15-ring chromosome because the critical location of the normal diaphragm development is at chromosome 15q26.1-q26.2.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 458-458
Author(s):  
Kajsa Paulsson ◽  
Jean-Baptiste Cazier ◽  
Jane Stevens ◽  
Tracy Chaplin ◽  
Finlay MacDougall ◽  
...  

Abstract The long-term disease-free survival rate of adult acute lymphoblastic leukemia (ALL) patients remains less than 40%, in contrast to pediatric cases where it approaches 80%. Furthermore, whereas genetic abnormalities are widely used in childhood ALL for assigning patients to prognostic risk groups, their use in adult ALL is generally restricted to the presence or absence of the t(9;22)/[BCR-ABL1]. Novel prognostic markers, allowing better treatment stratification, and new treatment targets are therefore much needed. We have investigated diagnostic samples from 45 adult ALL cases using genome-wide, high-resolution single nucleotide polymorphism (SNP) array analysis with the Affymetrix 10K, 250K Nsp, and 250K Sty chips, in total including more than 500,000 SNPs with a median inter-marker distance of <2.5 kb. This method, which has not previously been applied to adult ALL, enables the detection of genetic copy number abnormalities as well as uniparental disomies (UPDs) with a much higher resolution than cytogenetic and molecular genetic techniques. We detected 367 genetic abnormalities not corresponding to known copy number polymorphisms among the 45 cases. These comprised 94 copy number gains, 211 hemizygous deletions, 47 homozygous deletions, and 15 UPDs. All but three of the patients (93%) displayed one or more anomaly not detectable with standard genetic analyses. Most notably, we found high frequencies of deletions targeting the genes CDKN2A (P16) (21 cases; 47%), PAX5 (15 cases; 33%), IKZF1 (IKAROS) (8 cases; 18%), ETV6 (7 cases; 16%), RB1 (5 cases; 11%), and EBF1 (2 cases; 4.4%). Thirty-two cases (71%) harbored a deletion of at least one of these genes. CDKN2A deletions were homozygous in 17 cases and associated with partial UPDs in 5 cases. PAX5 deletions were always hemizygous and frequently large, including also CDKN2A in all but three patients. Notably, loss of IKZF1 was found in 5 of 10 (50%) t(9;22)/[BCR-ABL1]-positive ALL cases. Reverse transcriptase-PCR for this gene showed that some t(9;22)-positive cases without this deletion expressed a dominant-negative isoform of IKZF1, suggesting that different mechanisms for downregulation of IKZF1 occur and that this gene is frequently targeted in t(9;22)+ ALL. Furthermore, the SNP array analysis revealed novel recurrent deletions targeting the genes DLG2 (4 cases; 8.9%), LDOC1 (3 cases; 6.7%), ERBB4, and CDH13 (2 cases each; 4.4%). In conclusion, using high-resolution SNP arrays we detect a very high frequency of hidden genetic changes in adult ALL cases. Deletions, frequently cryptic, comprised 70% of the found abnormalities, suggesting that microdeletions are a characteristic feature of adult ALL. Most importantly, the analyses revealed recurrent genetic abnormalities in adult ALL targeting novel genes, not previously implicated in leukemogenesis. In addition to giving new insights into the leukemogenic process, these findings are likely to be clinically important, with the possibility of identifying new prognostic markers as well as future treatment targets in adult ALL.


2019 ◽  
Vol 47 (6) ◽  
pp. 651-655 ◽  
Author(s):  
Xiaoxi Zhao ◽  
Lin Fu

Abstract Background Classical karyotyping and copy-number variation sequencing (CNV-seq) are useful methods for the prenatal detection of chromosomal abnormalities. Here, we examined the potential of using a combination of the two methods for improved and accurate diagnosis. Methods From February 2013 to January 2018, 64 pregnant women showing indications for fetal chromosomal examination in the affiliated hospital of the Inner Mongolia Medical University were selected for this study. Amniotic fluid was collected and used for karyotype analysis and CNV-seq. Results Karyotype analysis of the 64 cases showed that six cases (9.38%) had chromosomal abnormalities. Using CNV-seq, in addition to three cases with numerical abnormalities of chromosomes, 14 cases were detected with CNV, of which five were pathogenic CNV, four were of uncertain clinical significance and five were polymorphic CNV. However, CNV-seq failed to detect one case with sex chromosome mosaicism and a balanced translocation carrier. The rate of abnormal chromosome and CNV detection was 26.56% (17/64) by CNV-seq. Conclusion Application of CNV-seq in prenatal diagnosis could allow the detection of submicroscopic chromosomal abnormalities and effectively reduce the birth of children with microdeletion and microduplication syndrome. Additionally, the combined application of karyotype analysis and CNV-seq can effectively improve the detection rate of chromosome abnormalities.


Author(s):  
Jerome J. Paulin

Within the past decade it has become apparent that HVEM offers the biologist a means to explore the three-dimensional structure of cells and/or organelles. Stereo-imaging of thick sections (e.g. 0.25-10 μm) not only reveals anatomical features of cellular components, but also reduces errors of interpretation associated with overlap of structures seen in thick sections. Concomitant with stereo-imaging techniques conventional serial Sectioning methods developed with thin sections have been adopted to serial thick sections (≥ 0.25 μm). Three-dimensional reconstructions of the chondriome of several species of trypanosomatid flagellates have been made from tracings of mitochondrial profiles on cellulose acetate sheets. The sheets are flooded with acetone, gluing them together, and the model sawed from the composite and redrawn.The extensive mitochondrial reticulum can be seen in consecutive thick sections of (0.25 μm thick) Crithidia fasciculata (Figs. 1-2). Profiles of the mitochondrion are distinguishable from the anterior apex of the cell (small arrow, Fig. 1) to the posterior pole (small arrow, Fig. 2).


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