Robertsonian translocation
A common and significant type of chromosome rearrangement that is formed by fusion of the whole long arms of two acrocentric chromosomes (chromosomes with the centromere near the very end). One in about 900 babies is born with a Robertsonian translocation making it the most common kind of chromosome rearrangement known in people. All five of the acrocentric chromosomes in people — chromosome numbers 13, 14, 15, 21 and 22 — have been found to engage in Robertsonian translocations. However, the formation of Robertsonian translocations was discovered by Hecht and coworkers to be highly nonrandom. Far and away the most frequent forms of Robertsonian translocations are between chromosomes 13 and 14, between 13 and 21, and between 21 and 22. In balanced form, a Robertsonian translocation takes the place of two acrocentric chromosomes and results in no problems for the person carrying it. But in unbalanced form, Robertsonian translocations produce chromosome imbalance and cause syndrome of multiple malformations and mental retardation. Robertsonian translocations between chromosomes 13 and 14 lead to the trisomy 13 (Patau) syndrome. And the Robertsonian translocations between 14 and 21 and between 21 and 22 can and do result in (trisomy 21 (Down) syndrome. Robertsonian translocations are named for the America insect geneticist W.R.B. Robertson who first described this form of translocation (in grasshoppers) in 1916 and are also known as whole-arm or centric-fusion translocations or rearrangements.

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(rob) translocation involving two acrocentric chromosomes (13, 14, 15, 21, and 22), which fuse at the centromere region and lose their heterochromatic short arms; since these short arms contain no essential genetic material, the rearrangement is considered to be a functionally balanced one. A carrier of a robertsonian translocation involving chromosomes 14 and 21 has a virtually complete chromosomal complement but only 45 chromosomes (including the translocation chromosome), is phenotypically normal, but risks producing offspring with trisomy 21 (translocation Down syndrome). See illustration at aberration.

Medical dictionary. 2011.

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  • Robertsonian translocation — is a common form of chromosomal rearrangement that occurs in the five acrocentric human chromosome pairs, namely 13, 14, 15, 21, and 22. They are named after the American insect geneticist W. R. B. Robertson, who first described a Robertsonian… …   Wikipedia

  • Robertsonian translocation — Robertsonian translocation. См. центрическое соединение. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Robertsonian translocation — A special type of non reciprocal translocation in chromosomes whereby the long arms of two non homologous acrocentric chromosomes are attached to a single centromere. The short arms become attached to form a reciprocal structure that however… …   Dictionary of molecular biology

  • symmetrical Robertsonian translocation — symmetrical Robertsonian translocation. = homologous Robertsonian translocation (см.). (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • homologous Robertsonian translocation — homologous Robertsonian translocation. См. гомологичная Робертсоновская транслокация. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • symmetrical Robertsonian translocation — symmetrical Robertsonian translocation. См. гомологичная Робертсоновская транслокация. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Translocation, Robertsonian — A relatively very common and medically significant type of chromosome rearrangement that is formed by fusion of the whole long arms of two acrocentric chromosomes (chromosomes with the centromere near the very end). One in about 900 babies is… …   Medical dictionary

  • translocation — 1. Transposition of two segments between nonhomologous chromosomes as a result of abnormal breakage and refusion of reciprocal segments. 2. Transport of a metabolite across a biomembrane. [trans + L. location, placement, fr. loco, to place]… …   Medical dictionary

  • Robertsonian — Rob·ert·so·ni·an .räb ərt sō nē ən adj relating to or being a reciprocal translocation that takes place between two acrocentric chromosomes and that yields one nonfunctional chromosome having two short arms and one functional chromosome having… …   Medical dictionary

  • robertsonian — ˌräbə(r)tˈsōnēən adjective Usage: usually capitalized Etymology: William R.B. Robertson died 1941 American biologist + English ian : relating to or being a reciprocal translocation that takes place between two acrocentric chromosomes and that… …   Useful english dictionary

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