Partial monosomy 7q34-qter and 21pter-q22.13 due to cryptic unbalanced translocation t(7;21) but not monosomy of the whole chromosome 21: a case report plus review of the literature.
| Autor: | Vorsanova SG; Institute of Human Genetics and Anthropology, Friedrich Schiller University, Jena, Germany. i8lith@mti.uni-jena.de., Iourov IY, Voinova-Ulas VY, Weise A, Monakhov VV, Kolotii AD, Soloviev IV, Novikov PV, Yurov YB, Liehr T |
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| Jazyk: | angličtina |
| Zdroj: | Molecular cytogenetics [Mol Cytogenet] 2008 Jun 19; Vol. 1, pp. 13. Date of Electronic Publication: 2008 Jun 19. |
| DOI: | 10.1186/1755-8166-1-13 |
| Abstrakt: | Background: Autosomal monosomies in human are generally suggested to be incompatible with life; however, there is quite a number of cytogenetic reports describing full monosomy of one chromosome 21 in live born children. Here, we report a cytogenetically similar case associated with congenital malformation including mental retardation, motor development delay, craniofacial dysmorphism and skeletal abnormalities. Results: Initially, a full monosomy of chromosome 21 was suspected as only 45 chromosomes were present. However, molecular cytogenetics revealed a de novo unbalanced translocation with a der(7)t(7;21). It turned out that the translocated part of chromosome 21 produced GTG-banding patterns similar to original ones of chromosome 7. The final karyotype was described as 45,XX,der(7)t(7;21)(q34;q22.13),-21. As a meta analysis revealed that clusters of the olfactory receptor gene family (ORF) are located in these breakpoint regions, an involvement of OFR in the rearrangement formation is discussed here. Conclusion: The described clinical phenotype is comparable to previously described cases with ring chromosome 21, and a number of cases with del(7)(q34). Thus, at least a certain percentage, if not all full monosomy of chromosome 21 in live-borns are cases of unbalanced translocations involving chromosome 21. |
| Databáze: | MEDLINE |
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