307:
22:
104:
203:(paired) or non-homologous chromosomes. Owing to the acrocentric nature of the chromosomes involved, the long arms of these chromosomes contain the majority of genetic material contained on the original chromosomes. The short arms also join to form a smaller reciprocal product, which typically contains only nonessential genes also present elsewhere in the genome, and is usually lost within a few
253:
A Robertsonian translocation results when the long arms of two acrocentric chromosomes fuse at the centromere and the two short arms are lost. If, for example, the long arms of chromosomes 13 and 14 fuse, no significant genetic material is lost—and the person is completely normal in spite of the
241:
A Robertsonian translocation in balanced form results in no excess or deficit of genetic material and causes no health difficulties. In unbalanced forms, Robertsonian translocations cause chromosomal deletions or addition and result in syndromes of multiple malformations, including trisomy 13
261:
Most people with
Robertsonian translocations have only 45 chromosomes in each of their cells, yet all essential genetic material is present, and they appear normal. Their children, however, may either be normal, carry the fusion chromosome (depending which chromosome is represented in the
94:
is present in our DNA in all four great apes this is split into two separate chromosomes typically numbered 2a and 2b. Similarly, the fact that horses have 64 chromosomes and donkeys 62, and that they can still have common, albeit usually infertile, offspring, may be due to a
Robertsonian
164:. Robertsonian translocations can only occur between chromosomes which have the centromere very close to one end. This means these chromosomes have a long arm which is particularly long, and a short arm which is particularly short. These are known as
277:
Rarely, the same translocation may be present homozygously if heterozygous parents with the same
Robertsonian translocation have children. The result may be viable offspring with 44 chromosomes. Outside of humans,
732:
Guarracino A, Buonaiuto S, Potapova T, Rhie A, Koren S, Rubinstein B, Fischer C, Gerton J, Phillippy A, Colonna V, Garrison E (2022). "Recombination between heterologous human acrocentric chromosomes".
64:. Robertsonian translocations result in a reduction in the number of chromosomes. A Robertsonian evolutionary fusion, which may have occurred in the common ancestor of humans and other
211:
visible, and can reduce chromosome number (in humans, from 23 to 22). However, the smaller chromosome carries so few essential genes that its loss is usually clinically insignificant.
348:
831:
Martinez-Castro P, Ramos MC, Rey JA, Benitez J, Sanchez Cascos A (1984). "Homozygosity for a
Robertsonian translocation (13q14q) in three offspring of heterozygous parents".
254:
translocation. Common
Robertsonian translocations are confined to the acrocentric chromosomes 13, 14, 15, 21 and 22, because the short arms of these chromosomes encode for
430:
227:
normal because there are two copies of all major chromosome arms and hence two copies of all essential genes. However, the progeny of this carrier may inherit an
358:, which includes band names, symbols and abbreviated terms used in the description of human chromosome and chromosome abnormalities. Abbreviations include
776:"Practice Guidelines for Communicating a Prenatal or Postnatal Diagnosis of Down Syndrome: Recommendations of the National Society of Genetic Counselors"
774:
Sheets KB, Crissman BG, Feist CD, Sell SL, Johnson LR, Donahue KC, Masser-Frye D, Brookshire GS, Carre AM, LaGrave D, Brasington CK (October 2011).
658:
602:
890:
Rajasekhar M, Rekharao RM, Shetty H, Gopinath PM, Satyamoorthy K (2010). "Cytogenetic
Analysis of 1400 Referral Cases: Manipal Experience".
1061:
314:
with annotated bands and sub-bands as used for the nomenclature of chromosome abnormalities. It shows dark and white regions as seen on
1056:
413:
E. Therman, B. Susman and C. Denniston. The nonrandom participation of human acrocentric chromosomes in
Robertsonian translocations.
48:
in humans, affecting 1 out of every 1,000 babies born. It does not usually cause medical problems, though some people may produce
463:"Centromere Destiny in Dicentric Chromosomes: New Insights from the Evolution of Human Chromosome 2 Ancestral Centromeric Region"
592:
219:
In humans, when a
Robertsonian translocation joins the long arm of chromosome 21 with the long arm of chromosomes 14 or 15, the
467:
437:
382:
334:
250:). The most frequent forms of Robertsonian translocations are between chromosomes 13 and 14, 14 and 21, and 14 and 15.
228:
53:
45:
306:
866:
37:
1051:
323:
200:
185:
181:
177:
173:
169:
279:
266:), or they may inherit a missing or extra long arm of an acrocentric chromosome (phenotype affected).
527:
68:, is the reason humans have 46 chromosomes while all other primates have 48. Detailed DNA studies of
1027:
915:
813:
756:
518:
267:
95:
evolutionary fusion at some point in the descent of today's donkeys from their common ancestor.
52:
with an incorrect number of chromosomes, resulting in a risk of miscarriage. In rare cases this
25:
A Robertsonian translocation. The short arms of the chromosomes (shown on right) are often lost
1019:
1011:
972:
954:
935:"Uniparental disomy in Robertsonian translocations: strategies for uniparental disomy testing"
907:
848:
805:
797:
714:
696:
654:
598:
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514:"An alignment-free method to find and visualise rearrangements between pairs of DNA sequences"
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146:
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704:
543:
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484:
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21:
271:
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192:, the two resulting long arms may fuse. The result is a single, large chromosome with a
967:
709:
684:
548:
513:
489:
462:
379:
330:
243:
107:
Chromosome arms can have different length ratios. Robertsonian translocation occurs in
61:
1045:
760:
363:
247:
235:
204:
57:
1031:
919:
817:
103:
903:
355:
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have 62; it is thought that the difference is due to a
Robertsonian translocation.
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91:
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165:
161:
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69:
41:
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Chiatante G, Giannuzzi G, Calabrese FM, Eichler EE, Ventura M (1 July 2017).
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73:
65:
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Chromosome studies. I. Taxonomic relationships shown in the chromosomes of
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498:
274:
is offered to families that may be carriers of chromosomal translocations.
1023:
1007:
852:
117:
in the image), where the short arms are fairly short but not very short.
362:
for
Robertsonian translocations. For example, rob(21;21)(q10;q10) causes
329:
chromosome pairs, both the female (XX) and male (XY) versions of the two
208:
991:
196:
centromere. This form of rearrangement is a Robertsonian translocation.
751:
231:
77:
844:
539:
295:
287:
263:
81:
49:
575:
283:
138:
122:
88:
20:
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385:(1881–1941) who first described a Robertsonian translocation in
255:
168:
chromosomes. Humans have five of these acrocentric chromosomes:
84:
649:
Hartwell L, Hood L, Goldberg M, Reynolds A, Silver L (2011).
44:
become fused to each other. It is the most common form of
512:
Pratas D, Silva RM, Pinho AJ, Ferreira PJ (18 May 2015).
374:
Robertsonian translocations are named after the American
349:
International System for Human Cytogenomic Nomenclature
152:
All chromosomes in animals have a long arm (known as
992:"Telomeres and mechanisms of Robertsonian fusion"
630:. V-shaped chromosomes and their significance in
431:"Unique: Rare Chromosome Disorder Support Group"
282:has 66 chromosomes, while both of domesticated
685:"Down Syndrome - Genetics and Cardiogenetics"
8:
653:. New York: McGraw-Hill. pp. 443, 454.
40:where the entire long arms of two different
966:
791:
750:
708:
547:
488:
673:Peter J. Russel; Essential Genetics 2003
351:(ISCN) is an international standard for
305:
188:. When these chromosomes break at their
102:
892:International Journal of Human Genetics
586:
584:
406:
199:This type of translocation may involve
871:Coriell Institute for Medical Research
898:(1–3). Kamla Raj Enterprises: 49–55.
258:which is present in multiple copies.
7:
867:"ISCN Symbols and Abbreviated Terms"
636:Gryllidae: chromosome and variation.
616:
614:
425:
423:
318:. Each row is vertically aligned at
160:), separated by a region called the
951:10.3978/j.issn.2224-4336.2014.03.03
651:Genetics From Genes to Genomes, 4e
14:
207:. This type of translocation is
468:Molecular Biology and Evolution
904:10.1080/09723757.2010.11886084
389:in 1916. They are also called
383:William Rees Brebner Robertson
1:
780:Journal of Genetic Counseling
395:centric-fusion translocations
16:Human chromosomal abnormality
990:Slijepcevic P (1998-05-01).
683:Plaiasu V (September 2017).
156:) and a short arm (known as
591:Chowdhary BP (2013-01-22).
1078:
1062:Chromosomal translocations
338:
87:has determined that where
30:Robertsonian translocation
1057:Chromosomal abnormalities
793:10.1007/s10897-011-9375-8
743:10.1101/2022.08.15.504037
597:. John Wiley & Sons.
113:chromosome pairs (number
46:chromosomal translocation
939:Translational Pediatrics
638:J Morph 1916;27:179-331.
415:Annals of Human Genetics
391:whole-arm translocations
38:chromosomal abnormality
632:Acrididae, Locustidae
344:
149:
26:
1008:10.1007/s004120050289
933:Yip MY (April 2014).
481:10.1093/molbev/msx108
339:Further information:
309:
106:
24:
833:Cytogenet Cell Genet
335:mitochondrial genome
570:More details under
532:2015NatSR...510203P
322:level. It shows 22
519:Scientific Reports
345:
337:(at bottom left).
280:Przewalski's horse
268:Genetic counseling
246:) and trisomy 21 (
150:
27:
845:10.1159/000132080
660:978-0-07-352526-6
604:978-1-118-52212-7
540:10.1038/srep10203
333:, as well as the
147:Sister chromatids
123:Short arm (p arm)
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475:(7): 1669–1681.
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436:. Archived from
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353:human chromosome
139:Long arm (q arm)
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620:Robertson WRB.
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331:sex chromosomes
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1002:(2): 136–140.
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417:1989;53:49-65.
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380:cytogeneticist
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244:Patau syndrome
225:phenotypically
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205:cell divisions
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62:Patau syndrome
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443:on 2019-02-18
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58:Down syndrome
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1052:Cytogenetics
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874:. Retrieved
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839:(4): 310–2.
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445:. Retrieved
438:the original
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394:
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387:grasshoppers
373:
359:
356:nomenclature
346:
302:Nomenclature
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260:
252:
240:
234:21, causing
221:heterozygous
218:
215:Consequences
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134:
126:
118:
109:
92:chromosome 2
33:
29:
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752:2117/393184
526:(1): 1203.
292:chromosomes
223:carrier is
194:metacentric
190:centromeres
166:acrocentric
110:acrocentric
56:results in
42:chromosomes
1046:Categories
996:Chromosoma
876:2022-10-27
624:Tettigidae
447:2019-02-17
401:References
324:homologous
320:centromere
229:unbalanced
201:homologous
162:centromere
131:Centromere
70:chimpanzee
66:great apes
1016:1432-0886
959:2224-4344
912:0972-3757
802:1059-7700
761:251647679
701:1841-9038
628:Acrididae
376:zoologist
341:Karyotype
327:autosomal
316:G banding
312:karyotype
99:Mechanism
74:orangutan
1032:11712171
977:26835328
920:55971437
818:19308113
810:21618060
719:29218069
558:25984837
499:28333343
290:have 64
286:and the
1024:9601982
968:4729106
853:6510025
735:bioRxiv
710:5706761
689:Maedica
549:4434998
528:Bibcode
490:5722054
296:donkeys
232:trisomy
78:gorilla
50:gametes
36:) is a
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310:Human
288:tarpan
284:horses
264:gamete
82:bonobo
1028:S2CID
916:S2CID
814:S2CID
757:S2CID
576:Hinny
441:(PDF)
434:(PDF)
89:human
1020:PMID
1012:ISSN
973:PMID
955:ISSN
908:ISSN
849:PMID
806:PMID
798:ISSN
715:PMID
697:ISSN
655:ISBN
626:and
599:ISBN
574:and
572:Mule
554:PMID
495:PMID
378:and
370:Name
347:The
294:and
270:and
256:rRNA
184:and
85:apes
80:and
60:and
1004:doi
1000:107
963:PMC
947:doi
900:doi
841:doi
788:doi
747:hdl
739:doi
705:PMC
634:and
544:PMC
536:doi
485:PMC
477:doi
393:or
360:rob
238:.
34:ROB
1048::
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1010:.
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994:.
971:.
961:.
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937:.
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784:20
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693:12
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473:34
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242:(
158:p
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