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- Repin, Mikhail V, et al.
(författare)
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New sequence-based data on the relative DNA contents of chromosomes in the normal male and female human diploid genomes for radiation molecular cytogenetics.
- 2009
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Ingår i: Molecular Cytogenetics. - : Springer Science and Business Media LLC. - 1755-8166. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: The objective of this work is to obtain the correct relative DNA contents of chromosomes in the normal male and female human diploid genomes for the use at FISH analysis of radiation-induced chromosome aberrations. RESULTS: The relative DNA contents of chromosomes in the male and female human diploid genomes have been calculated from the publicly available international Human Genome Project data. New sequence-based data on the relative DNA contents of human chromosomes were compared with the data recommended by the International Atomic Energy Agency in 2001. The differences in the values of the relative DNA contents of chromosomes obtained by using different approaches for 15 human chromosomes, mainly for large chromosomes, were below 2%. For the chromosomes 13, 17, 20 and 22 the differences were above 5%. CONCLUSION: New sequence-based data on the relative DNA contents of chromosomes in the normal male and female human diploid genomes were obtained. This approach, based on the genome sequence, can be recommended for the use in radiation molecular cytogenetics.
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- Gunnarsson, Cecilia, et al.
(författare)
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Chromosome r(10)(p15.3q26.12) in a newborn child : case report.
- 2009
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Ingår i: Molecular Cytogenetics. - : BioMed Central (BMC). - 1755-8166. ; 2, s. 25-
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: Ring chromosome 10 is a rare cytogenetic finding. Of the less than 10 reported cases we have found in the literature, none was characterized using high-resolution microarray analysis. Ring chromosomes are frequently unstable due to sister chromatid exchanges and mitotic failures. When mosaicism is present, the interpretation of genotype-phenotype correlations becomes extremely difficult. RESULTS: We report on a newborn girl with growth retardation, microcephaly, congenital heart defects, dysmorphic features and psychomotor retardation. Karyotyping revealed a non-mosaic apparently stable ring chromosome 10 replacing one of the normal homologues in all analyzed metaphases. High-resolution oligonucleotide microarray analysis showed a de novo approximately 12.5 Mb terminal deletion 10q26.12 -> qter and a corresponding 285 kb terminal deletion of 10pter -> p15.3. CONCLUSION: This case demonstrates that an increased nuchal translucency thickness detected by early ultrasonography should preferably lead to not only QF-PCR for the diagnosis of Down syndrome but also karyotyping. In the future, microarray analysis, which needs further evaluation, might become the method of choice. The clinical phenotype of our patient was in agreement with that of patients with a terminal 10q deletion. For the purpose of genotype-phenotype analysis, there seems to be no need for a "ring syndrome" concept.
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| 3. |
- Hulten, Maj A., et al.
(författare)
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On the paternal origin of trisomy 21 Down syndrome
- 2010
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Ingår i: Molecular Cytogenetics. - London, UK : BioMed Central (BMC). - 1755-8166. ; 3, s. 4-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Down syndrome (DS), characterized by an extra free chromosome 21 is the most common genetic cause for congenital malformations and learning disability. It is well known that the extra chromosome 21 originates from the mother in more than 90% of cases, the incidence increases with maternal age and there is a high recurrence in young women. In a previous report we have presented data to indicate that maternal trisomy 21 (T21) ovarian mosaicism might provide the major causative factor underlying these patterns of DS inheritance. One important outstanding question concerns the reason why the extra chromosome 21 in DS rarely originates from the father, i.e. in less than 10% of T21 DS cases. We here report data indicating that one reason for this parental sex difference is a very much lower degree of fetal testicular in comparison to ovarian T21 mosaicism. Results: We used fluorescence in situ hybridisation (FISH) with two chromosome 21-specific probes to determine the copy number of chromosome 21 in fetal testicular cell nuclei from four male fetuses, following termination of pregnancy for a non-medical/social reason at gestational age 14-19 weeks. The cells studied were selected on the basis of their morphology alone, pending immunological specification of the relevant cell types. We could not detect any indication of testicular T21 mosaicism in any of these four male fetuses, when analysing at least 2000 cells per case (range 2038-3971, total 11.842). This result is highly statistically significant (p < 0.001) in comparison to the average of 0.54% ovarian T21 mosaicism (range 0.20-0.88%) that we identified in eight female fetuses analysing a total of 12.634 cells, as documented in a previous report in this journal. Conclusion: Based on these observations we suggest that there is a significant sex difference in degrees of fetal germ line T21 mosaicism. Thus, it would appear that most female fetuses are T21 ovarian mosaics, while in sharp contrast most male fetuses may be either very low grade T21 testicular mosaics or they may be non-mosaics. We further propose that this sex difference in germ line T21 mosaicism may explain the much less frequent paternal origin of T21 DS than maternal. The mechanisms underlying the DS cases, where the extra chromosome 21 does originate from the father, remains unknown and further studies in this respect are required.
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| 5. |
- Hulten, MA, et al.
(författare)
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On the origin of trisomy 21 Down syndrome
- 2008
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Ingår i: Molecular cytogenetics. - : Springer Science and Business Media LLC. - 1755-8166. ; 1, s. 21-
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Tidskriftsartikel (refereegranskat)
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| 12. |
- Mandahl, Nils, et al.
(författare)
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Scattered genomic amplification in dedifferentiated liposarcoma
- 2017
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Ingår i: Molecular Cytogenetics. - : Springer Science and Business Media LLC. - 1755-8166. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Atypical lipomatous tumor (ALT), well differentiated liposarcoma (WDLS) and dedifferentiated liposarcoma (DDLS) are cytogenetically characterized by near-diploid karyotypes with no or few other aberrations than supernumerary ring or giant marker chromosomes, although DDLS tend to have somewhat more complex rearrangements. In contrast, pleomorphic liposarcomas (PLS) have highly aberrant and heterogeneous karyotypes. The ring and giant marker chromosomes contain discontinuous amplicons, in particular including multiple copies of the target genes CDK4, HMGA2 and MDM2 from 12q, but often also sequences from other chromosomes. Results: The present study presents a DDLS with an atypical hypertriploid karyotype without any ring or giant marker chromosomes. SNP array analyses revealed amplification of almost the entire 5p and discontinuous amplicons of 12q including the classical target genes, in particular CDK4. In addition, amplicons from 1q, 3q, 7p, 9p, 11q and 20q, covering from 2 to 14 Mb, were present. FISH analyses showed that sequences from 5p and 12q were scattered, separately or together, over more than 10 chromosomes of varying size. At RNA sequencing, significantly elevated expression, compared to myxoid liposarcomas, was seen for TRIO and AMACR in 5p and of CDK4, HMGA2 and MDM2 in 12q. Conclusions: The observed pattern of scattered amplification does not show the characteristics of chromothripsis, but is novel and differs from the well known cytogenetic manifestations of amplification, i.e., double minutes, homogeneously staining regions and ring chromosomes. Possible explanations for this unusual distribution of amplified sequences might be the mechanism of alternative lengthening of telomeres that is frequently active in DDLS and events associated with telomere crisis.
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