What is risk of neural tube defect in child, if either parent is born with spina bifida.
First, I need to recall the core concept here. Neural tube defects (NTDs) like spina bifida have a genetic component. The recurrence risk for NTDs in offspring when one parent is affected is typically around 4-10%, but if the parent has an NTD, the risk increases. Wait, if either parent has spina bifida, the risk is higher. Let me check standard references. Oh right, if one parent has an NTD, the risk is about 4-10%, but if both parents have an NTD, the risk jumps to 20-30%. But the question says either parent is born with spina bifida. So if one parent has it, the risk is 4-10%. The options might have been like 1%, 2%, 4%, 10%, etc. The correct answer is 4-10%, so the correct option would be the one that states that range.
Now, why is this the case? The core concept is the genetic predisposition to NTDs. Spina bifida is a multifactorial disorder with a strong genetic component. The risk increases if there's a family history. The exact mechanism isn't fully understood, but it's believed that multiple genes interact with environmental factors like folate levels. When one parent has an NTD, the offspring's risk is higher because of the inherited genetic factors. The mother's folate levels also play a role, hence the recommendation for folic acid supplementation before conception.
The incorrect options would be lower or higher than this range. For example, if an option says 1%, that's too low. If it's 15%, that's higher than the typical range. Also, if the parent has a different type of NTD, like anencephaly, the risk might vary slightly, but the general range for spina bifida would still be around 4-10%.
The clinical pearl here is that family history is a key risk factor, and preconception folic acid is crucial to reduce NTD risk. So the high-yield fact is the 4-10% risk when one parent has an NTD. The correct answer should reflect that range. Since the user didn't provide the options, I have to assume they included that range as one of the choices. The correct answer is the option that states 4-10%.
**Core Concept**
Neural tube defects (NTDs), including spina bifida, are multifactorial disorders with a significant genetic component. A family history of NTDs, particularly in first-degree relatives, increases the recurrence risk in offspring due to inherited susceptibility genes and shared environmental factors like folate deficiency.
**Why the Correct Answer is Right**
When one parent has spina bifida, the risk of NTDs in their child is **4–10%**, significantly higher than the general population risk of