Thursday, 3 September 2009

Some More Spectacular than others

From the BBC:
Each of us has at least 100 new mutations in our DNA, according to research published in the journal Current Biology.

Scientists have been trying to get an accurate estimate of the mutation rate for over 70 years.

However, only now has it been possible to get a reliable estimate, thanks to "next generation" technology for genetic sequencing.
Amongst other things, this means that "identical twins", those who were originally genetically identical before the embryonic clump of cells split into two individual foetuses, are unlikely to be completely genetically identical. In fact, it's likely that everyone has some cells of one genotype, and others of others, due to transcription errors during cell turnover.

Genetically, we are all unique. It's just that some of us have that uniqueness reflected more spectacularly than others.


MgS said...

Genetically, we are all unique. It's just that some of us have that uniqueness reflected more spectacularly than others.

Well Said!

Anonymous said...

I have heterochromia (no idea whether it is the inherited form or whether I am mosaic), one eye being light green the other dark brown. Every time I am trying to get a new passport I have to talk to some bureaucrat who insists that I am wearing contact lenses (I don't).

You have a choice of about five or so different colours on the passport application, and they all refer *to both eyes*.

The only way to explain to them that this is indeed my eye colour is to refer to David Bowie (he appears to have heterochromia but doesn't). Mentioning Alexander the Great (who in fact did have heterochromia, after all we can tell) doesn't work in my experience.

Even less promising is it to refer to the average rate of mutations in the human body. If it doesn't show, as in my case, people just don't want to hear it.

Great blog by the way!

Dr. B

Sara said...

Ah, but what of those that upon closer study do not appear to be random or if they are random, get passed on to offspring?

According to some fairly basic math by Stanford Prof. Joan Roughgarden, TS-ism (not differentiated by cause/type) occurs far, far more often than random mutation would indicate it should. And, as mentioned in "Family Cooccurrence of "Gender Dysphoria":
Ten Sibling or Parent-Child Pairs " (R.Green, 2000) and it's cited predecessor, Freund (1985), the prevalence of parent + child or sibling TS's in the same family are far above what they would be if caused by random mutation, on the order of 10 in 1500 gender clinic patients.

My question is, why have stats like these not prompted further study, as they would seem to indicate genetic etiologies that could be mapped?

oyunlar said...

Is there a possibility of them being sometimes the opposite?