If both parents have type 2 diabetes, the risk of inheritance of diabetes is
## **Core Concept**
The risk of inheritance of type 2 diabetes mellitus (T2DM) is influenced by both genetic and environmental factors. When both parents have T2DM, the offspring have a significantly higher risk of developing the disease compared to those with one or no affected parents. This is because T2DM has a strong familial component, with multiple genetic variants contributing to the risk.
## **Why the Correct Answer is Right**
When both parents have type 2 diabetes, the risk to their offspring is substantially increased. Studies have shown that if one parent has T2DM, the risk to offspring is about 20-40%. However, if both parents have T2DM, the risk to their children increases to approximately 50-60% or even higher in some populations. This increased risk is due to the higher genetic load of diabetes susceptibility genes inherited from both parents.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option underestimates the risk. Given that the risk with one affected parent is already significant, having both parents affected would logically increase this risk substantially beyond the figure provided here.
- **Option B:** Although this option might seem plausible, it still underestimates the risk compared to what is known when both parents are affected.
- **Option D:** This option overestimates the risk. While the risk is significantly increased with both parents having T2DM, stating it as 100% is incorrect because it does not account for the role of environmental factors and the possibility that offspring might not inherit all the susceptibility genes.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the risk of developing type 2 diabetes is also influenced by other factors including obesity, physical inactivity, and ethnicity. Offspring of parents with T2DM should be counseled on lifestyle modifications to reduce their risk, such as maintaining a healthy weight, engaging in regular physical activity, and following a balanced diet.
## **Correct Answer:** . 50-60% or more.