Final_2_Neurodevelopmental disorders: Down Syndrome

Question 1

genetic disorder and the

most common cause of intellectual disability

Answer 1

Down Syndrome

Question 2

How is Down syndrome diagnosed?

Answer 2

1. Prenatal screening

2. Karyotype: a profile of a person’s chromosomes

Question 3

Three different chromosomal abnormalities can

cause Down syndrome

Answer 3

1. Trisomy 21
2. Translocation
3. Mosaic

Question 4

error in cell division called “non-disjunction,”
results in an embryo with three copies of chromosomes
instead of two

Answer 4

Trisomy 21

Question 5

the total number of chromosomes in the
cells remains 46; however, an additional full or partial
copy of chromosome 21 attaches to another
chromosome, usually chromosome 14

Answer 5

Translocation

Question 6

the individual has a mixture of two types of cells,
some containing the usual 46 chromosomes and some
containing 47

Answer 6

Mosaic

Question 7

most DS patients develop

Answer 7

AD neuropathology by middle age

Question 8

Which of the following is a genetic abnormality leading to Down’s syndrome?

a. Robertsonian Translocation
b. CAG trinucleotide repeat
c. Trisomy 21

Answer 8

A and C only

Question 9

Which of the following are common brain abnormalities of Down Syndrome
patients?
a. Enlarged brain size
b. Overabundance of synapses
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c. Altered cortical lamination
d. Tau dephosphorylation

Answer 9

c. Altered cortical lamination

Question 10

There may be a genetic link between Down Syndrome and Alzheimer’s disease as
chromosome 21 also contains the gene coding for ___________________.

Answer 10

Amyloid Precursor Protein (APP)