<prompt> Which of the following is not associated with malignancy:Fragile X syndromeFanconis syndromeDowns syndromeBloom syndrome  <response>: Ans. is a Fragile X syndrome Fragile X syndrome is not associated with increased risk of malignancyDowns syndromeis associated with increased risk of leukemias.Fanconis syndrome and Blooms syndromebelong to autosomal recessive syndromes of defective DNA repair.These syndromes are associated with increased risk of malignancy. It includes:Fanconis syndromeBloom syndromeAtaxia telangiectasiaXeroderma pigmentosaFragile X syndromeIs the most frequent cause of hereditary mental retardation.It is caused by a fragile chromosomal site located on the distal long, arm of chromosome X. There is an amplification of a polymorphic CGG repeat in the fragile site.Cardinal characteristic of the condition is testicular enlargement macro orchidismOther clinical manifestations are:Mental retardationLarge size Long faceProminent jawLarge prominent earsStereotyped behaviour and speech 