What you carry at this position in your DNA and what research says about it.
Type 2 Diabetes Risk: 10/10 evidence, 35 publications.
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Sample genotype (not yours): C/C
Higher Risk of Type 2 Diabetes
Carrying two copies of the C allele is associated with a higher risk of developing type 2 diabetes and elevated fasting blood glucose levels. However, this genotype is linked to a lower risk of kidney complications if diabetes does occur.
What this genotype means: Elevated risk of type 2 diabetes; Higher fasting blood glucose levels; Lower risk of diabetic kidney complications.
Sample genotype (not yours): C/T
Lower Diabetes Risk but Higher Kidney Risk
This genotype presents a trade-off, offering protection against type 2 diabetes while increasing the risk of kidney complications if diabetes develops. It is also associated with a better response to certain diabetes medications.
What this genotype means: Reduced risk of developing type 2 diabetes; Moderately increased risk of diabetic nephropathy; Better response to gliclazide medication.
Sample genotype (not yours): T/T
Lowest Diabetes Risk but Highest Kidney Risk
Carrying two copies of the T allele significantly reduces the likelihood of developing type 2 diabetes. However, it is associated with the highest risk of diabetic kidney complications if diabetes is diagnosed.
What this genotype means: Significantly reduced risk of type 2 diabetes; Highest risk of diabetic nephropathy if diabetes occurs; Optimal response to gliclazide therapy.
Gene function and biological role
Gene Function: The KCNQ1 gene encodes a crucial subunit of voltage-gated potassium channels. These channels are highly active in both cardiac tissue and pancreatic beta-cells [1]. In the pancreas, they play a key role in regulating insulin secretion in response to glucose [1]. Genetic variations within this gene are strongly linked to susceptibility to metabolic conditions [2].
Variant Impact: The rs2237897 variant is located in an intron of the KCNQ1 gene and is thought to influence gene expression. Research indicates that the C allele is associated with impaired insulin secretion and higher blood sugar levels [1]. Conversely, the T allele appears to protect against diabetes but increases the risk of kidney complications in those who do develop the condition [3]. This creates a complex genetic trade-off between diabetes prevention and kidney health.
Key Insight: The T allele acts as a genetic trade-off, lowering the risk of developing type 2 diabetes but increasing the risk of kidney complications if diabetes does occur.
Location: KCNQ1. Chromosome 11 · 11p15.4 · 2.8 Mb
Estimated prevalence by population
Global 84.3%; European 92.1%; African 83.6%; East Asian 42.2%; South Asian 95.1%; Americas 62.2%; Ashkenazi 91.8%; Finnish 81.3%; Middle Eastern 89.4%; Amish 98.2%.
Estimated CC genotype frequency.
Global 14.5%; European 7.8%; African 15.7%; East Asian 45.5%; South Asian 4.9%; Americas 33.4%; Ashkenazi 8.1%; Finnish 17.7%; Middle Eastern 10.3%; Amish 1.7%.
Estimated CT genotype frequency.
Global 1.2%; European 0.2%; African 0.7%; East Asian 12.3%; South Asian 0.1%; Americas 4.5%; Ashkenazi 0.2%; Finnish 1.0%; Middle Eastern 0.3%; Amish < 0.1%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Cardiovascular & Metabolic
Diabetes & Glycemic Traits
Type 2 Diabetes. Evidence: 10/10. Source: PMID 18711366. ~1.25x Increased Risk.
Blood Glucose. Evidence: 9/10. Source: PMID 34594039. Higher Levels.
Organ Systems
Kidney Function & Disease
Diabetic Kidney Disease. Evidence: 4/10. Source: PMID 31324086. Typical Risk.
Pharmacogenomics
Diabetes Medication Response
Gliclazide Response. Evidence: 5/10. Source: PMID 26866747. Typical Response.
Showing effects for C/T genotype
Type 2 Diabetes. Evidence: 10/10. Source: PMID 18711366. Lower Risk.
Blood Glucose. Evidence: 9/10. Source: PMID 34594039. Typical Levels.
Diabetic Kidney Disease. Evidence: 4/10. Source: PMID 31324086. ~1.2x Increased Risk.
Gliclazide Response. Evidence: 5/10. Source: PMID 26866747. Stronger Response.
Showing effects for T/T genotype
Type 2 Diabetes. Evidence: 10/10. Source: PMID 18711366. Lowest Risk.
Diabetic Kidney Disease. Evidence: 4/10. Source: PMID 31324086. ~1.4x Increased Risk.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Fasting glucose levels and overall type 2 diabetes risk are elevated in those with the C/C genotype [1]. Large-scale genetic studies consistently identify the C allele as a primary risk factor for impaired beta-cell function [1]. A high global prevalence makes this the baseline genetic profile for the majority of people. While it increases the likelihood of developing diabetes, it is associated with a lower risk of diabetic nephropathy compared to T allele carriers [2]. If diabetes is diagnosed, standard clinical management remains highly effective.
Elevated risk of type 2 diabetes; Higher fasting blood glucose levels; Lower risk of diabetic kidney complications.
Sample genotype: CT (Heterozygous)
A balanced genetic profile is present in those with the C/T genotype, showing both protective and risk factors. The presence of one T allele reduces the overall risk of developing type 2 diabetes compared to the common C/C genotype [1]. However, if diabetes does develop, there is a moderately increased risk of diabetic nephropathy, a form of kidney damage [2]. Clinical studies also suggest that individuals with this genotype may experience a better therapeutic response to sulfonylurea medications like gliclazide [3]. This enhanced drug response can assist in achieving optimal blood sugar control. Proactive kidney health monitoring, such as routine urine albumin tests, is beneficial for managing potential complications. Emphasizing cardiovascular health and blood pressure control further supports long-term wellness.
Reduced risk of developing type 2 diabetes; Moderately increased risk of diabetic nephropathy; Better response to gliclazide medication.
Sample genotype: TT (Homozygous)
The lowest risk of developing type 2 diabetes is associated with the T/T genotype [1]. Despite this strong protective effect against diabetes, carrying two copies of the T allele significantly increases the risk of diabetic nephropathy if diabetes is diagnosed [2]. This dual effect represents a classic genetic trade-off between disease susceptibility and complication severity. Research also indicates a significantly better response to the antidiabetic drug gliclazide, which can help manage blood sugar effectively [3].
Significantly reduced risk of type 2 diabetes; Highest risk of diabetic nephropathy if diabetes occurs; Optimal response to gliclazide therapy.
Variants with shared genetic architecture
rs2074238 · KCNQ1 Gene · Chr 11 · Cardiac QT Interval
rs2237895 · KCNQ1 Gene · Chr 11 · Type 2 Diabetes Risk
rs2237892 · KCNQ1 Gene · Chr 11 · Type 2 Diabetes Risk
Identification of type 2 diabetes loci in 433,540 East Asian individuals.
KCNQ1 SNPS and susceptibility to diabetic nephropathy in East Asians with type 2 diabetes.
Association of KCNQ1 polymorphisms with gliclazide efficacy in Chinese type 2 diabetic patients.
Content updated August 2026.
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