robertsonian translocation

(redirected from Robertsonian)


the attachment of a fragment of one chromosome to a nonhomologous chromosome.
Translocation of a portion of one chromosome to another chromosome. Redrawn from Damjanov, 2000.
reciprocal translocation the mutual exchange of fragments between two broken chromosomes, one part of one uniting with part of the other.
robertsonian translocation that in which the breaks occur at the centromeres and entire chromosome arms are exchanged, usually involving two acrocentric chromosomes.

ro·bert·so·ni·an trans·lo·ca·tion

translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome consisting of the long arms of two different chromosomes with loss of the short arms. A carrier of a balanced robertsonian translocation has only 45 chromosomes but near normal chromosomal complement and a clinically normal phenotype; however, he or she is at risk of having a child with unbalanced chromosomal complement. A person with an unbalanced robertsonian translocation is trisomic for the long arm of the chromosome.
Synonym(s): centric fusion
[W.R.B. Robertson, U.S. geneticist.]

robertsonian translocation

the exchange of entire chromosome arms, with the break occurring at the centromere, usually between two nonhomologous acrocentric chromosomes. It produces one large, metacentric chromosome and one extremely small chromosome. The latter carries little genetic material and may be lost through successive cell divisions, leading to a reduction in total chromosome number. Compare balanced translocation, reciprocal translocation.
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Robertsonian translocation

ro·bert·so·ni·an trans·lo·ca·tion

(rob'ĕrt-sō'nē-ăn tranz'lō-kā'shŭn)
Translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome consisting of the long arms of two different chromosomes; if the translocation is balanced, the individual is clinically normal but a carrier of the translocation; if the translocation is unbalanced, the individual is trisomic for the long arm of a chromosome.
Synonym(s): centric fusion.
[W.R.B. Robertson, U.S. geneticist.]


W.R.B., U.S. geneticist, 1881–.
robertsonian translocation - translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome. Synonym(s): centric fusion

Robertsonian translocation

see Robertsonian translocation.
References in periodicals archive ?
Birth after intracytoplasmic injection of epididymal sperm from a man with congenital bilateral absence of the vas deferens who had a robertsonian translocation.
After cell-free DNA analysis became clinically available in 2011, ACOG and SMFM recommended it for women at increased risk of fetal aneuploidy, including women 35 years or older, fetuses with ultrasonographic findings indicative of an increased risk of aneuploidy, women with a history of trisomy-affected offspring, a parent carrying a balanced robertsonian translocation with an increased risk of trisomy 13 or trisomy 21, and women with positive first-trimester or second-trimester screening test results.
argentina located in central-eastern Argentina assessed for Robertsonian translocation and body size-related traits were considered in order to analyze simultaneous patterns of chromosome and body length variation (Colombo 1989, 1997).
Further subdivision of translocation types can be made according to the exchange of chromosomal material and are classified as: (i) reciprocal, when segments from two different chromosomes have been exchanged; or (ii) robertsonian, in five acrocentric chromosomes (13, 14, 15, 21 and 22), where long arms fuse to form a single chromosome with a single centromere.
The five high-risk criteria currently include maternal age 35 years or older at delivery; sonographic findings indicating an increased risk of aneuploidy; history of a prior pregnancy with a trisomy; positive screening results for aneuploidy, including first trimester, sequential, integrated, or quadruple screen; or parental balanced Robertsonian translocation with increased risk for trisomy 13 or 21.
There are also data showing that the sequencing test can be used to detect Down syndrome caused by robertsonian translocation, as well as chromosomal microdeletions.
Because we did not routinely perform karyotypes, we do not know the prevalence of underlying reproductive conditions such as Robertsonian translocations in our clinic sample.
43) An identical 13; 21 Robertsonian translocation was discovered in 2 other cases of mesenchymal chondrosarcoma, (37) but this abnormality is not characteristic of any specific tumor.
Robertsonian polymorphism in the marine gastropod, Nucella lapillus: advances in karyology using rDNA loci and NORs.
These discrepancies relate to the ease of Robertsonian translocation, principally with micro-chromosomes of bird species.
It involves methods of assay, including polymerase chain reaction and fluorescent in-situ hybridization, which are used to observe genetic abnormalities associated with monogenetic diseases like Huntington's and chromosomal abnormalities including Robertsonian translocations.
8 per cent of a Robertsonian translocation, which is respectively 6.