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: Biochemistry
Subtelomeric rearrangement of genes is frequently associated wih mental retardation. All of the following techniques can be used to diagnose them except: 
Select and explain. 
A. FISH, B. MAPH, C. cGH array, D. MALDI
D: MALDI
Answer: D: MALDI 
Explanation: D i.e. MALDISubtelomeric rearrangements of gene eg chromosomal duplications or deletions too small to be detected by conventional cytogentic analysis are detected by c-GH (comparative genomic hybridization), multiprobe FISH (fluorescence in situ hybridization), MAPH (multiplex amplifable probe hybridization) and MLPA (multiplex ligation-dependent probe amplification). Subtelomeric rearrangements are significant cause of idiopathic & familial mental retardation.