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Abdel Abdellaoui

@dr_appie

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Complex Trait Genetics | Population Genetics | Evolutionary Genetics | @AmsterdamUMC | @UvA_Amsterdam

Amsterdam, The Netherlands
Joined July 2015
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@dr_appie
Abdel Abdellaoui
2 years
Has it been 15 years already? Times flies when you have GWAS 🧬🎂 Check out our new review paper in @AJHGNews on the impressive range of GWAS discoveries with remarkable impact on multiple fields. Thank you @LoicYengo , Karin Verweij, and Peter Visscher:
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Abdel Abdellaoui
3 years
"We have incorporated all the reviewers' comments, which we believe has substantially improved our work"
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@dr_appie
Abdel Abdellaoui
2 years
This machine can do 75% of your PhD
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@dr_appie
Abdel Abdellaoui
3 years
Africa, if its borders were defined by ethnicity and language
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@dr_appie
Abdel Abdellaoui
3 years
I tried to summarize psychiatric genetics in a figure 🧬🧠
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@dr_appie
Abdel Abdellaoui
4 years
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@dr_appie
Abdel Abdellaoui
4 years
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@dr_appie
Abdel Abdellaoui
3 years
Academia: train people to get really good at doing research, then have them spend all their time applying for money so they can hire people that they can train to get really good at research so they can also spend all their time applying for money so they can hire etc
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@dr_appie
Abdel Abdellaoui
3 years
Looking for a hypothesis that fits your data
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@dr_appie
Abdel Abdellaoui
3 years
Development of the human brain from 0 to 100 years old 🧠 Based on >120k brain scans from >100k people:
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@dr_appie
Abdel Abdellaoui
2 years
Genetic effects shared between major psychiatric disorders and a range of behavioral outcomes. Source:
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@dr_appie
Abdel Abdellaoui
2 years
Men are less likely than women to pass on genes associated with ADHD, depression, schizophrenia, neuroticism, or autism, while being more likely to pass on genes associated with extraversion, education, or height 🧬 For more sex differences see figure or:
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@dr_appie
Abdel Abdellaoui
2 years
We tend to reward people with certain genetic propensities with better environments (higher SES 💰). This results in gene-environment correlations that make society more unequal and further complicate studying human genetics. Out now in @NatureGenet : 🧵👇🏽
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@dr_appie
Abdel Abdellaoui
4 years
I've been developing & teaching this GWAS course since 2009, but will not be teaching it anymore. Some of the material survived since 2009, some of it only appeared recently. Feel free to use anything, this link contains slides, literature, and practicals:
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@dr_appie
Abdel Abdellaoui
3 years
Check out our new @NatureHumBehav article, where we review the history and current state of behavioural genetics and explain how we can further our understanding of the complex relationship between DNA & human behaviour 🧬🤸🏽‍♂️🧠 -
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@dr_appie
Abdel Abdellaoui
4 years
Complex trait genetics
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@dr_appie
Abdel Abdellaoui
1 year
This is how elephants rub their eyes. You're welcome ♥️
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@dr_appie
Abdel Abdellaoui
1 month
The largest investigation to date on not having had sex late in life: Our study of >400 thousand individuals links sexlessness to higher education, lower substance use, personality, mental health, physical traits, regional characteristics, and genetics.
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@dr_appie
Abdel Abdellaoui
2 years
Elon Musk should buy 23andMe and release all GWAS summary statistics
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@dr_appie
Abdel Abdellaoui
2 years
Genes associated with whether you ever tried cannabis are associated with higher IQ and higher education. Genes associated with cannabis addiction are associated with lower IQ and lower education. More on genetics of cannabis use in our new review: 🧬🥦
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@dr_appie
Abdel Abdellaoui
1 year
A dozen major psychiatric conditions interwoven by shared genetic effects 🧬🧠
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@dr_appie
Abdel Abdellaoui
1 year
Unraveling the genetic architecture of complex traits with genome-wide association studies
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Abdel Abdellaoui
5 years
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@dr_appie
Abdel Abdellaoui
3 years
Am I doing this right?
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@dr_appie
Abdel Abdellaoui
11 months
The field of human genetics is evolving at a rapid pace. Much of this progress is driven by our recent ability to link common DNA variants to complex traits with genome-wide association studies (GWASs) 🧬 For both newcomers and seasoned geneticists, good review papers can be
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Abdel Abdellaoui
3 years
Industry scientists seem to be more satisfied than those in academia 🧑🏽‍🔬💰 Academia must step its game up
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@dr_appie
Abdel Abdellaoui
2 years
Genes associated with ADHD or depression are passed onto more offspring by females than by males. Genes associated with higher extraversion, lower neuroticism, or lower autism risk are passed down more often by males. More sex differences below 👇🏽 From:
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@dr_appie
Abdel Abdellaoui
10 months
Genes that increase the chances of getting addicted to alcohol increase the risk of feeling lonely. Genes that increase the risk for autism increase IQ. Genes that increase the risk for anorexia increase the chances of getting a higher education 🧬🧠
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@dr_appie
Abdel Abdellaoui
1 year
According to the biggest human family tree to date, computed from DNA from ~3,600 modern and ~3,600 ancient individuals, early humans originated in Sudan ~2 million years ago 🧬💀 -
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@dr_appie
Abdel Abdellaoui
3 years
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@dr_appie
Abdel Abdellaoui
5 years
"If everyone smoked 20 cigarettes a day, then case-control & cohort studies would lead us to conclude that lung cancer is a genetic disease" From this interesting piece on "sick individuals and sick populations": How would mental health fit into this?
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@dr_appie
Abdel Abdellaoui
1 year
Two slides explaining polygenic scores 🧬
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@dr_appie
Abdel Abdellaoui
3 years
"We're the least genetically diverse great ape; 2 groups of chimps from Congo are more genetically different from each other than 2 groups of humans plucked from Berlin & Beijing. Most of our diversity is cultural." Quote: Figure:
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@dr_appie
Abdel Abdellaoui
5 years
Our study on the geographic distribution of human DNA in Great Britain is out in @NatureHumBehav . You can download a general summary and FAQ document here: The article is here: And a thread explaining the main findings below 👇🏾
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@dr_appie
Abdel Abdellaoui
1 year
Many small neuroimaging studies have probably reported false positive findings. Especially for traits related to cognition & mental health, thousands of subjects are required 🧠 New paper from our talented PhD student Shu Liu in @NatureHumBehav :
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@dr_appie
Abdel Abdellaoui
3 years
Genetic effects that influence where you live can induce gene-environment correlations that confound GWASs. We show that controlling for geography reduces heritability for SES and reduces genetic correlations with SES for many traits. Our new preprint:
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@dr_appie
Abdel Abdellaoui
4 years
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@dr_appie
Abdel Abdellaoui
2 years
Genetic relationships between psychiatric disorders 🧬🧠
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@dr_appie
Abdel Abdellaoui
3 years
The heritability of educational attainment for women was close to zero around 1900, in line with the scarcity of opportunities women had to cultivate their talents through education. It increased to ~60% near the end of the century.
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@dr_appie
Abdel Abdellaoui
4 years
I have a joke about gene-environment interactions, but you won't be able to replicate it
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@dr_appie
Abdel Abdellaoui
3 years
Between all these behavioural traits, the highest genetic correlation (i.e., most genetic effects shared) is between educational attainment and income 🎓🧬💰 Source:
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@dr_appie
Abdel Abdellaoui
3 years
This detailed model of a human cell makes me suspect that maybe nature is not really a puzzle meant to be solved, but rather a party to be celebrated
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@dr_appie
Abdel Abdellaoui
3 years
Funny story: my parents didn't get to finish primary school, I have a PhD, and study the heritability of educational attainment 🤔🤷🏽‍♂️
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@dr_appie
Abdel Abdellaoui
4 years
Males are more likely to be left-handed than females, and the number of left-handed people seems to increase over time 🤔 Why? Data is from @uk_biobank
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@dr_appie
Abdel Abdellaoui
2 years
A century ago, height helped to reconcile Mendel’s laws with the inheritance of complex traits. Now, @LoicYengo et al made it the first trait to have all its common genetic effects captured, which predict better than the parental average. This is major. -
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@dr_appie
Abdel Abdellaoui
2 years
A historic milestone in genetics coming in three days 🧬🔥
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@dr_appie
Abdel Abdellaoui
6 years
I have an idea for a dating app. Non-Africans carry 1-2% Neanderthal DNA, but collectively they carry 40% of the Neanderthal genome. The app matches people with non-overlapping Neanderthal DNA. If this gets popular enough, we could recreate 40% Neanderthal - 60% human persons! 🐵
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@dr_appie
Abdel Abdellaoui
3 years
I dedicate this Manhattan plot of a GWAS on testicle size to all the brave Ukrainian soldiers and citizens that are putting up a fight 🇺🇦
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@dr_appie
Abdel Abdellaoui
1 year
Everything is connected 🧬 Genes that increase the risk of alcohol addiction tend to increase loneliness. Genes that increase risk of autism increase IQ. Genes that increase anorexia risk increase education. My piece in @bigthink on behavior genetics:
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@dr_appie
Abdel Abdellaoui
5 years
What kind of genetic propensities are associated with the quality of your life? See Figure below for estimated genetic correlations (= measure for shared genetic influences) between 55 heritable traits and subjective wellbeing.
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@dr_appie
Abdel Abdellaoui
2 years
Out now in @BehaviorGenetic : genes associated with higher education are selected against, i.e., passed onto fewer offspring. The direction of this selection pressure is reversed in older mothers, i.e., first child at > ~22 years old. @davidhughjones 🧬🎓
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@dr_appie
Abdel Abdellaoui
4 years
The new schizophrenia GWAS is finally out: 69,369 cases, 236,642 controls, and 270 hits. Preprint:
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@dr_appie
Abdel Abdellaoui
4 years
Many psychiatric disorders and substance use outcomes share genetic effects. Controlling for genes associated with socio-economic outcomes changes the genetic relationships between these mental health outcomes. Our paper just out in @NatureHumBehav 🧬💸🧠
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@dr_appie
Abdel Abdellaoui
3 years
The heritability of a trait is not informative for explaining group differences
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@dr_appie
Abdel Abdellaoui
3 years
All behavioural traits are heritable. Thanks to large-scale GWAS studies, we now know that this is due to many genes with very small effects. How much larger do GWASs need to get before we capture the total heritability with measured DNA? Figure from:
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@dr_appie
Abdel Abdellaoui
3 years
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@dr_appie
Abdel Abdellaoui
2 years
Why aren't we collecting more DNA from the most diverse continent 🧬
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@dr_appie
Abdel Abdellaoui
4 years
Exactly 1 decade ago today, this little guy joined us using half my genome 🥳
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@dr_appie
Abdel Abdellaoui
2 years
Which paper(s) have taught you a lot about genetics? 📃🧬
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@dr_appie
Abdel Abdellaoui
1 year
Winner of the Fulker award (article of the year) from @BehaviorGenetic : One of the findings: women pass on more genes associated with ADHD, depression, schizophrenia, or autism, and men more genes associated with extraversion, education, or height 🧬
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@dr_appie
Abdel Abdellaoui
2 years
Modern genetics research reveals that part of the answer to the nature/nurture debate lies in the way we organize our society. Would it be possible to find answers to how we should organize our society in the nature/nurture question?
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@dr_appie
Abdel Abdellaoui
1 year
Sometimes having a higher genetic risk for a psychiatric disorder can also be associated with positive outcomes 🧬🧠 The figure below shows shared genetic effects between psychiatric disorders and a range of behavioral traits (source: )
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@dr_appie
Abdel Abdellaoui
4 years
What does it mean when genes are associated with intelligence? Much of genetic influences underlying IQ aren't unique to IQ. Here is the estimated overlap between genes associated with IQ (based on ) and a bunch of other traits (rg = genetic correlation).
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@dr_appie
Abdel Abdellaoui
3 months
The genetic correlation between IQ and subjective wellbeing is zero
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@dr_appie
Abdel Abdellaoui
3 years
New @NatureHumBehav paper on evolutionary selection pressures on 870 complex traits 🧬⌛️ They conclude that pigmentation, body measurements, and nutrition-related traits showed the most continuous and strong selection pressures throughout human history.
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@dr_appie
Abdel Abdellaoui
1 year
The journey of the human brain, from birth to 100 years old 🧠 Based on over 120k brain scans from more than 100k individuals:
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@dr_appie
Abdel Abdellaoui
6 years
World map showing where GWAS participants come from 🤔 Source:
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@dr_appie
Abdel Abdellaoui
4 years
Genetic effects associated with education, cognition, ADHD, and smoking have stronger associations with brain structure, while genes for other psychiatric disorders show stronger associations with brain function (N🧬&🧠 = 37k). Check out our new preprint:
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@dr_appie
Abdel Abdellaoui
4 years
While the polygenic score for height has been decreasing in Great Britain throughout the last century, actual height has consistently increased. Environment wins! (data = ~450k @uk_biobank participants)
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@dr_appie
Abdel Abdellaoui
4 years
Here are ~450 thousand @uk_biobank participants moving from their birthplace to their current address and back. For more on migration in Great Britain, see:
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@dr_appie
Abdel Abdellaoui
2 years
Genes associated with sexuality & reproduction also impact a range of other traits. These outcomes are particularly interesting for genetics because they show a snapshot of natural selection 🧬 Figure from More on natural selection
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Abdel Abdellaoui
4 years
Genes associated with physical appearance diverged faster than other genes. Our visual & tribal propensities may have been the selection pressure causing people to socially cluster based on appearance, making groups of people look more different over time than they actually are.
@dr_appie
Abdel Abdellaoui
4 years
The geographic distribution of the genetic variant that codes for blue/brown eye colour. If you inherit two G alleles, the chance of blue eyes is ~99%. It has clearly been under some type of selection for it to be so common in some and so absent in other populations.
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@dr_appie
Abdel Abdellaoui
4 years
Associations between genes and complex behavioral outcomes reflect a composite of genetic effects on lower-level phenotypes and environmental effects that are correlated with those genetic effects. Figure comes from:
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@dr_appie
Abdel Abdellaoui
2 years
I did a GWAS on musical ability and the Manhattan plot came out partying
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@dr_appie
Abdel Abdellaoui
2 years
Genetics
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@dr_appie
Abdel Abdellaoui
5 years
The income GWAS got many twitter reactions, almost all negative. The educational attainment GWAS got generally positive reactions. Income: EA: Their genetic correlation is >.9. Why the opposite reactions to almost the same study?
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@dr_appie
Abdel Abdellaoui
8 months
"Almost everything is heritable" A short overview of the history, current state, and future of psychiatric genetics 🧬🧠 English: Original in Dutch:
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@dr_appie
Abdel Abdellaoui
1 year
I see lots of angry tweeting about Greg Clark's new paper. I don't know how right or how wrong he is, but I do know that he shared all his data! 👏👏👏 So, less tweeting and more sciencing you science kardashians, get to work
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Abdel Abdellaoui
3 years
"biological" and "social construct" are not mutually exclusive
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@dr_appie
Abdel Abdellaoui
3 years
The next game is: extract the causal SNPs from these GWAS summary statistics
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Abdel Abdellaoui
2 years
I was scheduled to give the opening keynote lecture at this year's @ISIRonline conference in Vienna, but when I saw in the program that @KirkegaardEmil would be speaking, I had to cancel. There is no way I will be on the same speaker list as that careless racist lunatic. (1/4)
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@dr_appie
Abdel Abdellaoui
3 years
Genetic correlations between covid-19 outcomes and cognition, personality, behavior, and physical & mental health 🧬😷
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@dr_appie
Abdel Abdellaoui
1 year
Genetic correlations between 26 behavioral traits and 26 physical traits 🧬 High quality pdf:
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@dr_appie
Abdel Abdellaoui
3 years
My favourite genetics project so far is watching this little guy grow up 🧬❤
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@dr_appie
Abdel Abdellaoui
4 years
Genes survive natural selection pressures by being passed on to offspring. Below is a measure of natural selection in modern humans of European descent, namely the genetic correlation with nr of offspring based on European GWAS results.
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@dr_appie
Abdel Abdellaoui
3 years
New GWAS on height is the biggest genetics study to date with 5.4 million individuals 😯 The top ~12k genetic variants explain ~40% of individual differences in Europeans, and 10-20% in other ancestries.
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@dr_appie
Abdel Abdellaoui
1 year
Among the major psychiatric disorders, schizophrenia and bipolar disorder share most genetic effects (genetic correlation = ~0.7) 🧬🎭 They also have a very similar genetic correlation profile with other traits:
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@dr_appie
Abdel Abdellaoui
1 year
A dozen major psychiatric conditions interwoven by shared genetic effects 🧬🧠
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@dr_appie
Abdel Abdellaoui
6 months
The International Statistical Genetics Workshop, annually held in Boulder, has its video lectures and practicals organized on a user-friendly website accessible to the global community, which will be further expanded as the field evolves 🧬📏
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@dr_appie
Abdel Abdellaoui
3 years
Reality probably looks nothing like the model our brain makes for us to observe
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@dr_appie
Abdel Abdellaoui
4 years
The power of sample size
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@dr_appie
Abdel Abdellaoui
2 years
Assortative mating is prevalent across species, often with respect to body size and color. In humans, partners resemble each other most for social traits 🥰 (data for the figure was taken from this meta-analysis by @GeneWilderType & @matthewckeller : )
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Abdel Abdellaoui
1 year
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Abdel Abdellaoui
2 years
Here is a world map of child malnutrition and infection for all the people posting similar maps of cognitive outcomes claiming genetic differences as the cause
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@dr_appie
Abdel Abdellaoui
4 years
Grant reviewer: what question do you want to answer with your research? Me:
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@dr_appie
Abdel Abdellaoui
3 years
The heritability of IQ varies between socio-economic groups: in the US, genes explain fewer individual differences in IQ in economically disadvantaged families than in richer families, likely because the former lack means to facilitate the expression of genetic potential.
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@dr_appie
Abdel Abdellaoui
3 years
The heritability of educational attainment for women was close to zero around 1900, in line with the scarcity of opportunities women had to cultivate their talents through education. It increased to ~60% near the end of the century.
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Abdel Abdellaoui
2 years
Peter Visscher: "In my opinion, genomics should be fully embedded into the social sciences. If a substantial portion of differences between people in important life outcomes is due to DNA, why not utilise it to design better experiments and inform policy?"
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@dr_appie
Abdel Abdellaoui
3 years
I did this once
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Abdel Abdellaoui
2 years
The drop in whole-genome sequencing costs on a logarithmic and a linear scale
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Abdel Abdellaoui
3 years
Relationships between functional brain measures and polygenic scores for mental health, cognition, and educational attainment. From:
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Abdel Abdellaoui
3 years
The first page of my PhD thesis #DarwinDay 🎅🏼
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