Mechanism of Dementia in Downs Syndrome

Which of the following is responsible for dementia seen in adults with Down’s syndrome?

A. Loss of genetic material in chromosome 21
B. Extra genetic material in chromosome 21
C. Genetic material lost from chromosome 14
D. Loss of genetic material corresponding to presenilin -1
E. Loss of genetic material corresponding to Apoe4

Ok extra genetic material is the correct answer. The gene that codes for b amyloid is located on chromosome 21. Since down syndrome is due to trisomy 21 so there is increased amount of genetic material that production of its product proteins. Product protein of the APP gene located on chromosome 21 is beta amyloid that is central to the aetiology of alzheimers