Question:medium
What is the approximate risk of genetic diseases in a consanguineous marriage between first cousins?
What is the approximate risk of genetic diseases in a consanguineous marriage between first cousins?
Show Hint
First cousin risk is roughly double the general 2-3% birth defect rate.
Updated On: Jun 23, 2026
- 1-2%
- 4-8%
- 8-10%
- 12-14%
Show Solution
The Correct Option is B
Solution and Explanation
Step 1: First cousins carry a measurable proportion of shared genes, raising the chance that both parents transmit the same recessive allele and produce a homozygous affected child.
Step 2: The baseline prevalence of birth defects in the general population sits near $2$ to $3\%$.
Step 3: Empirically the risk in first cousin marriages runs at roughly twice this baseline, landing around $4$ to $6\%$.
Step 4: The only choice that brackets this doubled risk is the $4$ to $8\%$ option.\[\boxed{4\text{-}8\%}\]
Step 2: The baseline prevalence of birth defects in the general population sits near $2$ to $3\%$.
Step 3: Empirically the risk in first cousin marriages runs at roughly twice this baseline, landing around $4$ to $6\%$.
Step 4: The only choice that brackets this doubled risk is the $4$ to $8\%$ option.\[\boxed{4\text{-}8\%}\]
Was this answer helpful?
0
