Answer- D. Bloom syndromeUniparental disomy is the term used when both chromosome of a pair of chromosome is a person with normal number of chromosome, have been inherited from only one parent (Normally one chromosome of a pair is inherited from only one parent).The two chromosomes inherited from the same parent maybe identical (Uniparental isodisomy) or different (Uniparental heterodisomy).In Uniparental isodisomy, both chromosomes in the pair are identical; consequently the genes on both chromosomes are also identical.Angelman syndrome, Prader-Willi syndrome and Russell-Silver syndrome are ossociated with uniparental disomy.