Each page covers one condition properly: what it actually is and what it feels like, what causes it, how common it really is and in whom, and how it's diagnosed — followed by the specific variants with a replicated link to it, and, where the research supports it, how genetics can change the way a medicine behaves.
Written in two registers so one page serves both readers: plain language first, then a clinical detail section with the precise terminology, effect sizes and diagnostic thresholds. Every claim is sourced from freely-available published research and cited on the page, so you can check us — or hand the page to your doctor. 385 conditions so far, growing continuously, and free to reuse with attribution (CC BY 4.0).
53 results in Trait
Not how much bone an adult has lost, but how it is built in the first place. Two studies of children's bone development found the skeleton is not one trait — different sites have different genetics — and one study found a gene that trades off muscle against bone at the exact same locus.
Read more → TraitThe proxy measure nearly all bone genetics research actually uses, from a single study of 142,487 people that went unusually far to check its statistical findings against real mouse biology — including 120 knockout mice.
Read more → TraitA common anthropometric measurement whose genetics are real and well-mapped — and whose relationship to disease risk runs the opposite way "bigger measurement, worse outcome" intuition suggests. Smaller hip circumference, not larger, tracks with more heart disease.
Read more → TraitWhich bacteria live in the gut, and in what proportion, is measurably shaped by host genetics — not just diet. Two independent 2016 studies, in German and Dutch cohorts, each found real genetic associations, with two results — one about vitamin D, one about lactose — that come with an obvious mechanism attached.
Read more → TraitYears of schooling completed, studied genome-wide in nearly 300,000 people and then 1.1 million. A real, replicated signal exists — and even at its largest scale it explains barely a tenth of the variance in the one thing it was built to predict, in a trait shaped enormously by the society someone grows up in.
Read more → TraitA real, heritable disposition toward risk-seeking, mapped across hundreds of genome positions in over a million people. It explains a real slice of why people differ as a population, and essentially nothing about any one person's genotype.
Read more → TraitWhen baby teeth and adult teeth come in is more heritable than most people would guess — twin studies put it above 80%. Nine variants across three large studies mark some of that heritability, in genes that also shape height and facial width.
Read more → Trait449,484 people, 136 positions, 599 genes — and the most interesting result is that the trait split in two. What one questionnaire measures as one thing turned out to be two genetically distinguishable things.
Read more → TraitThe largest study of how long people live looked at a million parents. What came out top was not a repair gene or a telomere gene — it was Alzheimer's risk, then smoking, then cholesterol, then heart disease, then blood pressure. There is no longevity gene in the results. There are disease genes, and not dying of those things is most of what a long life is.
Read more → TraitWhen puberty starts is heritable, polygenic, and moved by years within a century — which tells you how much of it is not genetic. One of the variants here is the same position this site carries for obesity, and that overlap is the mechanism, not a coincidence.
Read more → TraitThe textbook polygenic trait, with the number usually left out: 12,111 positions, none of which means anything alone. It is also the clearest demonstration of why a genetic score built in one population predicts badly in another.
Read more → TraitOne position explains most of whether eyes are blue or brown — which is why the brown-dominant, blue-recessive square from school is wrong. The same genes that shade normal color cause albinism when they break outright.
Read more → TraitThe ABO gene variant that creates blood type O by disabling its enzyme, why blood type matters for transfusion, and which disease links (clotting risk, malaria, cholera) are strong versus which (COVID-19, cancer risk) remain modest or contested.
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One diagnosed condition or measurable trait covered properly: what it actually is, what causes it, how common it is, how it is diagnosed, and the specific variants with a replicated link to it — every claim sourced from published research.
No. Every page here is informational, not a diagnosis. A result should be discussed with a doctor or a licensed genetic counselor, never acted on alone.
Because they are not disorders. Height, ABO blood group and a handful of others describe a measurable characteristic with nothing to diagnose — "Trait" says so plainly instead of implying a disease that is not one.
Only after a replicated association in published research, verified against the primary study rather than a gene name or a marketing claim — the same discipline the variant pages themselves follow.