<prompt> Memory impairment is most likely to occur in :Downs SyndromeAlkaptonuriaAttention deficit disorderConduct disorder  <response>: Answer is A Downs Syndrome : Patients with Downs syndrome Trisomy 21 frequently develop lesions of Alzheimers disease in the third or fouh decade of life. Memory impairment forms an impoant characteristic of Alzheimers disease and Downs syndrome thus may be considered as a predictor of memory impairment in later life 