My mother in DNA.LAND

My mother, Beryl Seel, died on the 3rd of December 2015 aged 92. In August the previous year I had persuaded her to spit into the 23andMe sample collection tube and get sequenced.

"Now we can bring you back," I murmured, but she didn't seem keen.

I understand 23andMe pussyfooting around, not wishing to fall foul of the US regulators yet again. This means DNA.LAND if you want to play with polygenic scores. I uploaded her genome subset (the 23andMe downloaded text file) and here are some of the results.

As usual, click on an image to make it large enough to read.

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This is the top-level screen showing some of the traits they can begin to predict

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Educational attainment

My mother was predicted to have 14.7 years of schooling (two years at university). In fact she had 9, leaving school in 1937 as a 14 year old.

My prediction from DNA.LAND is also 14.7 years but in fact I had 19 years equivalent full-time education. Clare was predicted to have 14.4 years yet she is a graduate with an additional teacher-training qualification.

Heritability of EA is low and the small numbers of relevant SNPs available to DNA.LAND makes even the genetic component estimate a very noisy measure. See the discussion below.

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Intelligence and IQ

This is marked as 'very preliminary' which - as they are quoting only 16 SNPs - seems about right.

Heritability of IQ is of the order of 80% but given this few genetic markers the signal will be swamped by the effects of all the other relevant SNPs which are unknown and whose contributions are therefore unmeasured.

About all you can say in favour of the exercise is that correlations between IQ-enhancing alleles based on an underlying soft sweep probably gives this slightly more predictive power than one might naively expect.

Note also we don't get a central IQ estimate with error bars. The normal distribution curve above is referenced to the DNA.LAND sign-up population, with unknown IQ parameters.

Anyway, FWIW, my mother seems to be one IQ point above the DNA.LAND average based on a super-noisy regression line.

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Neuroticism

Neuroticism (emotionalism, anxiety) is one of the 'five factor' personality traits and is the opposite to emotional stability, calmness on this dimension. There are strong gender differences in this factor, women scoring as more emotional.

I have memories of a fair degree of maternal emotionalism, but perhaps that was par for the course.

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Height

My DNA.LAND polygenic score was 182 cm, which is exactly right. My mother's (above) equates to 5' 7". That is taller than I remember, perhaps by an inch. I recall that growing up in the 1930s was not a picnic. My father was just under six foot.

My parents on their engagement: is she taller than average?

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Discussion

How seriously should we take all this? Not very, at this point (except for height, where PGS scores are accurate predictors of genomic potential - although DNA.LAND aren't using the latest estimators).

Example regression line for scatter plot with correlation 0.38

The correlations between the small numbers of SNPs currently being used by DNA.LAND and the physical/cognitive variables they're trying to predict are very low. Educational attainment was discussed on their website as follows:

"Overall, educational attainment is estimated to have a heritability of around 20%. This means that in a population of individuals with varying years of education, 20% of that variation can be explained by variants in the individuals' genomes."

So the polygenic score will give the phenotype value on the regression line, but the true value could be a long way up or down depending on life events. My mother, a working class girl, left school at 14 for example. Nobody does that today.

Thousands of SNPs are implicated in complex polygenic traits like those listed above, yet relatively few are currently known (except for height) .. and DNA.LAND uses only those publicly available (a tiny subset). So their regression lines will be pretty inaccurate.

Finally, note that my mother is positioned with respect to DNA.LAND's user population which is self-selected. We don't know how the norms for this group compare to the general population.

It will get better, even if we're a way from the option of bringing her back.