What is the Link Between Down Syndrome and Familial Alzheimer's

Question

What is the link between Down syndrome and familial Alzheimer's disease?
A) The APP gene is located on Chromosome 21, which has an extra copy in Down syndrome.
B) The APP gene is located on Chromosome 14, which is the duplicated chromosome in Down syndrome.
C) The presenilin 1 and 2 gene is located on Chromosome 21, which is the duplicated chromosome in Down syndrome.
D) The presenilin 1 and 2 gene is located on Chromosome 14, which is the duplicated chromosome in Down syndrome.

Accepted Answer

Down syndrome is caused by having an extra Chromosome 21, which has the gene for APP. Therefore people with Down syndrome have an extra copy of the APP gene and have early-onset AD.