Molecular Genetics of Down Syndrome Flashcards Preview

Developmental Genetics > Molecular Genetics of Down Syndrome > Flashcards

Flashcards in Molecular Genetics of Down Syndrome Deck (22):
1

Down syndrome is the most common cause of..

- Mental retardation and Congenital Heart Disease.

2

What are the characteristics of Down Syndrome? (morphology)

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3

What are the systemic conditions associated with down syndrome?

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4

What are the variable symptoms associated with down syndrome?

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5

What is the basic cause of DS?

Mainly imbalance in chromosomes on Chr21. However, partial segmental duplication or partial trisomy of Chr21 can also result in DS (5%).

6

What is the incidence, Clinical Features, Aetiology, and Recurrence Risk of DS?

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7

What is the down syndrome critical region?

~5.4mb from (prox) D21S17/D21S55 to (distal) MX1 / BCEI.

8

What is the DSCR associated with?

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9

Define synteny.

the physical co-localization of genetic loci on the same chromosome within an individual or species. Today, however, biologists usually refer to synteny as the conservation of blocks of order within two sets of chromosomes that are being compared with each other.

10

Which mouse chromosome is similar to chr21?

16

11

What else shares conserved mouse regions to chr21 apart from 16?

17 and 18.

12

How did they use mice to provide an animal model for human DS?

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13

What did Reeves et al., 1995 find?

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14

Cerebellar volume in mice is significantly ________ in Ts65Dn mice.

As well as ____

Reduced.

Granule cell density.

15

What did 'Parallels of Craniofaial Maldevelopment in Down Syndrome and Ts65Dn mice' show?

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16

What are alternative hypotheses for the molecular basis of DS?

1. Nonspecific perturbation of balanced genetic programs
(Quantitative or developmental instability hypothesis)

2. Simple, Mendelian-like influence of a small subset of genes
(Down Syndrome critical region (DSCR) hypothesis)

17

What did 'A chromosome 21 critical region does not cause specific down syndrome phenotypes' show/conclude?

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18

Possible explanations?

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19

What is Yu et al.s Proposed mouse model for DS?

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20

What does Dp(10)(16)(17) mutant mice exhibit?

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21

What is the likely basis of DS?

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22

What is the effect of Sonic the Hedgehog Agonist Therapy?

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