Markers / Condition
Which genes are linked to type 2 diabetes?
Type 2 diabetes is strongly heritable and strongly environmental at the same time, which sounds contradictory and is not: the genes set how much insulin your pancreas can produce and how well it is used, and the environment decides how much is asked of that system. Hundreds of common variants each contribute a little. These are the ones with the largest individual effects, and the ones whose frequencies differ most between populations.
The markers
| Marker | Gene | What it does | Evidence |
|---|---|---|---|
| rs7903146 | TCF7L2 | Type 2 diabetes, the strongest common variant | established |
| rs13266634 | SLC30A8 | The zinc transporter inside insulin granules | established |
| rs7756992 | CDKAL1 | CDKAL1 and how much insulin you release | established |
| rs2237892 | KCNQ1 | The diabetes variant that Europe nearly missed | established |
| rs5219 | KCNJ11 | KCNJ11, the channel that sulfonylurea drugs act on | established |
| rs75493593 | SLC16A11 | Neanderthal: a diabetes risk variant carried into the Americas | established |
| rs1421085 | FTO | FTO, the body weight variant | established |
| rs17782313 | near MC4R | MC4R, appetite regulation | established |
Type 2 diabetes, the strongest common variant
rs7903146 · TCF7L2
Of the hundreds of common variants linked to type 2 diabetes, this one has by far the largest effect and has replicated in essentially every population studied. It appears to act on insulin secretion rather than on insulin resistance.
Two copies: Two higher-risk copies, roughly twice the background risk
The zinc transporter inside insulin granules
rs13266634 · SLC30A8
Insulin is stored in the pancreas packed around zinc, and this transporter loads the zinc in. The variant version is associated with lower risk of type 2 diabetes. Unusually, rare mutations that break the gene completely are protective too, which is why it became a drug target.
Two copies: You have the lower-risk version on both copies
CDKAL1 and how much insulin you release
rs7756992 · CDKAL1
One of the first type 2 diabetes variants found, and one of the few that replicates in every population tested. It acts on how much insulin the pancreas puts out rather than on how well the body responds to it.
Two copies: You have the higher-risk version on both copies
The diabetes variant that Europe nearly missed
rs2237892 · KCNQ1
KCNQ1 was found by studying Japanese populations, not European ones, and it is one of the strongest type 2 diabetes signals in East Asia. It is a reminder that a genetics built only on European samples finds only the variants Europeans have, which is a real and ongoing problem in the field.
Two copies: You have the higher-risk version on both copies
KCNJ11, the channel that sulfonylurea drugs act on
rs5219 · KCNJ11
This potassium channel is the trigger that tells a pancreatic cell to release insulin. It is also exactly what the sulfonylurea class of diabetes drugs binds to, which makes this one of the few diabetes variants with a direct line to treatment.
Two copies: You have the higher-risk version on both copies
Neanderthal: a diabetes risk variant carried into the Americas
rs75493593 · SLC16A11
A Neanderthal-derived version of a sugar and fat transporter, carried by roughly half of people with Indigenous American ancestry and about one in ten in East Asia, and rare elsewhere. It is one of the clearest cases of archaic DNA shaping modern disease risk unevenly across populations.
Two copies: Inherited from both parents
FTO, the body weight variant
rs1421085 · FTO
The best-known common variant affecting body weight. This particular position is the one shown experimentally to be the cause rather than merely a marker: it disrupts a control site so that developing fat cells switch towards storing energy instead of burning it.
Two copies: Two higher-weight copies, about three pounds on average
MC4R, appetite regulation
rs17782313 · near MC4R
MC4R sits at the centre of the brain circuit that decides when you feel full. Rare severe mutations in it cause childhood obesity; this common variant nearby nudges appetite in the same direction, far more gently.
Two copies: Two copies of the higher-appetite version
Which versions do you carry?
All of these are readable from an ordinary home DNA test file, in your browser, without uploading it anywhere.
Read my fileCommon questions
Which genes are linked to type 2 diabetes?
Type 2 diabetes is strongly heritable and strongly environmental at the same time, which sounds contradictory and is not: the genes set how much insulin your pancreas can produce and how well it is used, and the environment decides how much is asked of that system. Hundreds of common variants each contribute a little. These are the ones with the largest individual effects, and the ones whose frequencies differ most between populations. The markers most often cited are rs7903146 in TCF7L2, rs13266634 in SLC30A8, rs7756992 in CDKAL1, rs2237892 in KCNQ1, rs5219 in KCNJ11.
What does rs7903146 do?
Of the hundreds of common variants linked to type 2 diabetes, this one has by far the largest effect and has replicated in essentially every population studied. It appears to act on insulin secretion rather than on insulin resistance. Carrying two copies: two higher-risk copies, roughly twice the background risk.
What does rs13266634 do?
Insulin is stored in the pancreas packed around zinc, and this transporter loads the zinc in. The variant version is associated with lower risk of type 2 diabetes. Unusually, rare mutations that break the gene completely are protective too, which is why it became a drug target. Carrying two copies: you have the lower-risk version on both copies.
What does rs7756992 do?
One of the first type 2 diabetes variants found, and one of the few that replicates in every population tested. It acts on how much insulin the pancreas puts out rather than on how well the body responds to it. Carrying two copies: you have the higher-risk version on both copies.
What does rs2237892 do?
KCNQ1 was found by studying Japanese populations, not European ones, and it is one of the strongest type 2 diabetes signals in East Asia. It is a reminder that a genetics built only on European samples finds only the variants Europeans have, which is a real and ongoing problem in the field. Carrying two copies: you have the higher-risk version on both copies.
Reference information, not medical advice and not a diagnosis. See the medical disclaimer.