This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Phenomenon called anticipation is seen in? 
Select and explain. 
A. Mitochondrial inheritance, B. x - linked dominant disorders, C. Trinucleotide repeat expansion, D. Genomic imprinting
C: Trinucleotide repeat expansion
Answer: C: Trinucleotide repeat expansion 
Explanation: Instablity of triplet repeats can lead to gradual expansion from generation to generation,a phenomenon called anticipation,Genetic anticipation is characterized  by the reduction in the age of disease onset  by successive genarations.