This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Trinucleotide repeat seen in Fragile X syndrome is 
Select and explain. 
A. CGG, B. CTG, C. CAG, D. GAA
A: CGG
Answer: A: CGG 
Explanation: Examples of Trinucleotide-Repeat DisordersDiseaseRepeatFragile X syndromeCGGFriedreich ataxiaGAAMyotonic dystrophyCTGSpinobulbar muscular atrophy(Kennedy disease)Huntington diseaseSpinocerebellar ataxiaCAGRef: Robbins and Cotran Pathologic Basis of Disease; 9th edition; Chapter 5; Genetic Disorders; Page no: 168