Are you a mutant?

Most probably. A study arising from the 1000 Genomes Project has shown that we each inherit around 60 new mutations (on average) from our parents – this is much lower than the previous estimate, which was based on comparisons between human and chimpanzee DNA. This is the first ever study to measure directly the mutations arising from parents.

Published in Nature Genetics, the research was based on whole genome sequencing of two sets of mother-father-child, and was led by researchers from the UK-based Wellcome Trust Sanger Institute, joined by teams from the USA and Canada.

In the study, de novo mutations were much more common in the paternal line (up to 92%) than the maternal line in one set, fitting with the theory that the increased number of copies of DNA required to create the sperm throughout the father’s lifetime, compared with the eggs, which are all already created at the mother’s birth, allows more ‘errors’ to creep in. However, in the other set, there were more errors in the maternal line (64%). This may not negate the theory and may just show an increased variation between families. It is also worth bearing in mind that this was only a very small sample – larger studies are required to see if this is a general trend.

These mutations have driven evolution, and this new data could push the date of the common ancestor for humans and apes back to around 7 million years ago. On a practical note, the data could be used to estimate the impact on public health of older fathers, as the mutations are higher in the male line. The data also show that there is a wide variation in inheritance within families – this could perhaps explain why siblings are sometimes so different. Though it’s perhaps not a good idea to use the term ‘mutant’ in your next argument with your brother or sister…

We welcome today’s guest post from Suzanne Elvidge, editor of the Genome Engineering blog.

3 Responses to “Are you a mutant?”

  1. Thanks for the chance to guest blog!

  2. It’s interesting work and does tell us some interesting things but as you rightly point out, it’s a small sample (n=2). Still probably a lot more useful than previous human-chimpanzee studies!

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