robertsonian translocation

(redirected from Robertsonian fusion)


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 ?
irradians may not be a selective advantage, but rather because of an evolutionary loss of telomeres through Robertsonian fusion and extensive chromosome arm loss.
This reduction in chromosome number may be because of Robertsonian fusion, wherein telocentric chromosomes fused, reducing the total chromosome number (Wang & Guo 2004).
1987), thus, contradicting the hypothesis of reduction of chromosome number by Robertsonian fusion in the taxa distributed outside the Andean plateau.
Robertsonian fusion and centric fission are unique in being readily identified in comparative karyotype studies since both result in concomitant changes in chromosome morphology and chromosome number.
Robertsonian fusion has been demonstrated as a significant mechanism of karyotype evolution in several genera of the Tradescantieae where it can be regarded as a type of chromosome ortho-selection.
These analyses have been performed with these characters ordered with and without polarity, that is, with and without the possibility of reversing a Robertsonian fusion.
An alternative hypothesis would postulate that the first extension of populations of the CA clone toward Spain occurred before Robertsonian fusions appeared in the species studied here (except for tu).
No consensus exists as to the cause of the high frequency of Robertsonian fusion mutations in house mice (but see Redi et al.
Later, I discussed statispatry directly with Michael White; it was when I had caught those first house mice with a re-arranged karyotype due to Robertsonian fusions.
domesticus mice (2n = 34) from this region due to the presence of three centric or Robertsonian fusions, Rb(2.
Robertsonian fusions between X chromosomes and autosomes (X/A fusion) have occurred many times in the evolutionary history of South American Melanoplinae which exhibit an amazing diversity of neo-XY chromosome systems (Mesa et al.
After Robertsonian fusions take place (Saez 1963, White 1973), agradual process of heterochromatinization in the exhomologues begins.