Unstable Repeat Expansions

Question 1

Fragile X is caused by…

Answer 1

Expansion of a CGG repeat in the 5’ UTR of Exon #1 of the FMR1 gene

Question 2

Large FMR1 expansions tend to happen in…

Answer 2

Mothers

Question 3

FrX double digest…whats that all about..

Answer 3

Check around the Eag1 region. If super methylated, then you’ll lose the ability to cleave there, making a 5.2 kb rather than a 2.4 and a 2.8

Question 4

Inheritance of Myotonic Dystrophy

Answer 4

Autosomal Dominant

Question 5

Symptoms of Myotonic Dystrophy

Answer 5

Progressive muscle weakness and wasting
Begins in face (masklike)
Early Cataracts
Heart Conduction defects, endocrine/repro defects

Question 6

What is anticipation

Answer 6

Progressively earlier onset and/or increased severeity of disease in successive generations of a family

Question 7

Gene in myotonic dytrophy

Answer 7

DMPK has expanded CUG repeats

Question 8

Myotonic dystrophy type II gene/genetic info

Answer 8

DM2 geme,
CUG repeat into first intron of ZNF9
RNA gain to negative fxn

Question 9

Fredreich ataxia symptoms include

Answer 9

Ataxia, dysarthria, diminished reflexes

Question 10

Fredreich ataxia is caused by…

Answer 10

Expansion of a non-coding region of the frataxin gene

Gene important for Iron metabolism

Question 11

Most affected cells in Huntington

Answer 11

GABA-releasing spiny neorons onf the striatum

Question 12

Genetic information about Huntington

Answer 12

Huntingtin Gene CAG repeats (over 40)

Question 13

Repeats tend to expand more when transmitted by…

Answer 13

Males