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How often do chromosomal rearrangements occur?


I am interested about these kind of chromosomal rearrangements that are passed on to the descendants, i.e. germ line chromosomal rearrangements. The value I am looking for is similar to the mutation rate but only take into account major mutations such as chromosomal rearrangements.

Supposing there might have some important variance in this rate among species, then I am interested in eukaryotes and particularly in plants. If needed, the answer can be split into the different types of chromosomal rearrangements (robertsonian translocation, other translocations, inversions, ...)

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    $\begingroup$ You can have a look at these papers: 1, 2. Gotta go now. will post an answer when I get time. $\endgroup$ – WYSIWYG Sep 26 '14 at 14:46
  • $\begingroup$ Just to clarify; you are asking only about larger chromosomal rearrangements (as in translocations, inversions, deletions etc), and not the frequency of also "normal" chromosome crossovers between homologous chronosomes? $\endgroup$ – fileunderwater Sep 26 '14 at 17:50
  • $\begingroup$ Yes, indeed, I am interested in major chromosomal rearrangements and not about normal standard cross-overs. $\endgroup$ – Remi.b Sep 26 '14 at 18:25
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    $\begingroup$ @WYSIWYG must be really busy... $\endgroup$ – RenaissanceProgrammer Aug 18 '17 at 21:32
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    $\begingroup$ @RenaissanceProgrammer I was free for quite some time between Sep 2014 and now but nobody reminded me then. I am busy again now :/ $\endgroup$ – WYSIWYG Aug 19 '17 at 6:56
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Obviously, there won't be a single number for this.

The phenomenon is fairly well understood in yeast. Unfortunately, most studies tend to focus on the rate of formation of specific well-understood rearrangements, and then use that as a baseline. I am having trouble finding a measurement of overall rearrangement rate, although the system is ideal for this.

There has been some work on characterizing rates of rearrangement (and its evolution) across evolutionary history, I don't know if that is directly relevant.

This paper has a decent breakdown of the incidences in humans across different kinds of translocations. For example:

Additional studies (5, 6) followed and the incidence of balanced translocations was ultimately determined to be 1 in 500 in the general population.

Studies using cleavage stage biopsy for reciprocal translocation PGD have reported proportions of unbalanced embryos as high as 82% (57).

There is good reason to expect that it varies significantly across species and across chromosomes. For example, the Drosophila Y is a hotspot.

And (first paper):

Rearrangements involving chromosomes 13 and 14 (der(13;14)(q10;q10)) account for 75% of Robertsonian translocations (12).

For an early paper looking at a large population, you can see here.

Note that most of these human numbers are indicative of population incidence rather than rate of occurrence. Others have attempted to study effects on the translocation rate directly.

The best citation that I found for directly measuring translocation rate is here. However, the data are apparently for somatic translocations and are rather unevenly sampled so I am unsure of how generalizable it is. I looked at WYSIWYG's papers and they might provide some specific examples but they don't seem to address translocation rate directly either.

Take-home, it's hard to directly measure rearrangement rate in humans due to inviability of many/most aneuploidies early after fertilization. Somatic is easier to estimate but may not be representative of rearrangements in the gametes.

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