|
1
|
Poot M, Hochstenbach R. Prevalence and Phenotypic Impact of Robertsonian Translocations. Mol Syndromol 2021; 12:1-11. [PMID: 33776621 PMCID: PMC7983559 DOI: 10.1159/000512676] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Robertsonian translocations (RTs) result from fusion of 2 acrocentric chromosomes (e.g., 13, 14, 15, 21, 22) and consequential losses of segments of the p arms containing 47S rDNA clusters and transcription factor binding sites. Depending on the position of the breakpoints, the size of these losses vary considerably between types of RTs. The prevalence of RTs in the general population is estimated to be around 1 per 800 individuals, making RTs the most common chromosomal rearrangement in healthy individuals. Based on their prevalence, RTs are classified as "common," rob(13;14) and rob(14;21), or "rare" (the 8 remaining nonhomologous combinations). Carriers of RTs are at an increased risk for offspring with chromosomal imbalances or with uniparental disomy. RTs are generally regarded as phenotypically neutral, although, due to RTs formation, 2 of the 10 ribosomal rDNA gene clusters, several long noncoding RNAs, and in the case of RTs involving chromosome 21, several mRNA encoding genes are lost. Nevertheless, recent evidence indicates that RTs may have a significant phenotypic impact. In particular, rob(13;14) carriers have a significantly elevated risk for breast cancer. While RTs are easily spotted by routine karyotyping, they may go unnoticed if only array-CGH and NextGen sequencing methods are applied. This review first discusses possible molecular mechanisms underlying the particularly high rates of RT formation and their incidence in the general population, and second, likely causes for the elevated cancer risk of some RTs will be examined.
Collapse
Affiliation(s)
- Martin Poot
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Ron Hochstenbach
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
|
2
|
Redaelli S, Conconi D, Villa N, Sala E, Crosti F, Corti C, Catusi I, Garzo M, Romitti L, Martinoli E, Patrizi A, Malgara R, Recalcati MP, Dalprà L, Lavitrano M, Riva P, Roversi G, Bentivegna A. Instability of Short Arm of Acrocentric Chromosomes: Lesson from Non-Acrocentric Satellited Chromosomes. Report of 24 Unrelated Cases. Int J Mol Sci 2020; 21:ijms21103431. [PMID: 32413994 PMCID: PMC7279238 DOI: 10.3390/ijms21103431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/09/2020] [Accepted: 05/11/2020] [Indexed: 01/13/2023] Open
Abstract
Satellited non-acrocentric autosomal chromosomes (ps–qs-chromosomes) are the result of an interchange between sub- or telomeric regions of autosomes and the p arm of acrocentrics. The sequence homology at the rearrangement breakpoints appears to be, among others, the most frequent mechanism generating these variant chromosomes. The unbalanced carriers of this type of translocation may or may not display phenotypic abnormalities. With the aim to understand the causative mechanism, we revised all the ps–qs-chromosomes identified in five medical genetics laboratories, which used the same procedures for karyotype analysis, reporting 24 unrelated cases involving eight chromosomes. In conclusion, we observed three different scenarios: true translocation, benign variant and complex rearrangement. The detection of translocation partners is essential to evaluate possible euchromatic unbalances and to infer their effect on phenotype. Moreover, we emphasize the importance to perform both, molecular and conventional cytogenetics methods, to better understand the behavior of our genome.
Collapse
Affiliation(s)
- Serena Redaelli
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Donatella Conconi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Nicoletta Villa
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Elena Sala
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Francesca Crosti
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Cecilia Corti
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Ilaria Catusi
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Maria Garzo
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Lorenza Romitti
- Pathology and Cytogenetics Laboratory, Clinical Pathology Department, Niguarda Ca’ Granda Hospital, 20162 Milan, Italy;
| | - Emanuela Martinoli
- Medical Genetics Laboratory, Medical Biotechnology and Translational Medicine Department, University of Milan, 20090 Milan, Italy; (E.M.); (P.R.)
| | - Antonella Patrizi
- Medical Cytogenetics Laboratory, Clinical Pathology Department, San Paolo Hospital, 20142 Milan, Italy; (A.P.); (R.M.)
| | - Roberta Malgara
- Medical Cytogenetics Laboratory, Clinical Pathology Department, San Paolo Hospital, 20142 Milan, Italy; (A.P.); (R.M.)
| | - Maria Paola Recalcati
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Leda Dalprà
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Marialuisa Lavitrano
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Paola Riva
- Medical Genetics Laboratory, Medical Biotechnology and Translational Medicine Department, University of Milan, 20090 Milan, Italy; (E.M.); (P.R.)
| | - Gaia Roversi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Angela Bentivegna
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
- Correspondence: ; Tel.: +39-0264488133
| |
Collapse
|