This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cellular Pathology, Subject name: Pathology
Linkage disequilibrium refers to? 
Select and explain. 
A. Never co-inherited gene, B. Inherited but not with disease causing gene, C. Genetic mutations, D. Co-inherited with the disease causing gene
D: Co-inherited with the disease causing gene
Answer: D: Co-inherited with the disease causing gene 
Explanation: Ans. (d) Co-inherited with the disease causing gene(Ref: Robbins 9th/pg 3)Even if any SNP has no effect on gene function (Neutral SNP) Q, it may be co-inherited with the "actual disease causing gene," if located close to that gene. This is called "Linkage disequilibrium" Q