<prompt> Increasing severity of mental retardation of male members over generations is a result of -Mitochondrial DNA mutationFrameshift mutationY linked disorderTrinucleotide repeat mutation  <response>: Ans. d Trinucleotide repeat mutationRef: Robbins 9thpg 168-171; 8thpg 168-171Increasing severity of mental retardation of male members over generations is a result of anticipation, seen in disorders caused by Trinucleotide repeat mutation. Eg Fragile X syndrome 