This short article on the Independent’s website may not be the worst piece of genetics reporting ever, but given its brevity it may well take a new record for the density of errors and misconceptions. (To save you the trouble of hunting down the article it’s actually referring to, which of course is not linked, it’s this online article in Molecular Psychiatry).
Let’s start with the headline:
Sleeping is all in the genes
No. Data from twin studies suggest that the length of time people sleep for is around 44% heritable – that is, around 44% of the variation in this trait is due to inherited (and presumably mostly genetic) factors. The article being discussed in the piece provides no new information about the heritability of this trait.
Scientists have found the reason why some people need more sleep than others lies in their genes.
Scientists have found that one of the reasons people sleep longer than others is possibly a variant in a non-coding region of the gene ABCC9. Even if this association is real (and the evidence in the article is less than compelling), it explains just 5% of the variation in sleep length between people.
A survey of more than 10,000 people …
A survey of 4,251 people found the association between sleep length and the ABCC9 variant. This association was not replicated in a separate set of 5,949 individuals. The authors have a potential explanation for this lack of replication (based on the season in which the sleep length measurements were collected), and then did a post hoc re-analysis of their combined sample accounting for season that produced positive results.
showed those carrying the gene ABCC9, present in one in five of us,
The gene ABCC9 is present in all of us (hell, it’s even present in fruitflies). However, there is a genetic variation in one region of the ABCC9 gene, and one version of this variation is present in 17.3% of Europeans.
slept longer than the average of eight hours. The finding, which is published in Molecular Psychiatry,
This is true! The article is indeed published in Molecular Psychiatry. Well done.
could explain why Margaret Thatcher only needed four hours a night as Prime Minister while Albert Einstein was said to sleep for 11.
We do not know the genotype at this variant in either Margaret Thatcher or Albert Einstein. However, given the very small effects of this variant on the variation in sleep length within the population, we can say unambiguously that this variant does not explain the difference in sleepy-time between these two famous individuals.
Time is tight, and deadlines wait for no man. We should forgive the author of this piece for his more subtle errors – but there is no excuse for the “gene present in one in five of us” blunder.
Well, at least the headlines haven’t descended into complete populist madness and screamed about “the Thatcher gene”. OH NO.