Lecture 6 - Unstable Repeat Expansions 2

Question 1

myotonic dystrophy:
repeat of _____;
repeats located in.. 3’ or 5’ region? translated or untranslated?

Answer 1

CTG;

3’ untranslated

Question 2

myotonic dystrophy:
eyes = _____,
testicular ____;
can’t ____ muscle

Answer 2

cataracts, atrophy, relax

mask like face due to muscle wasting

Question 3

myotonic dystrophy:
gene affected?
mutant ____ accumulates in foci in the ____

Answer 3

DM protein kinase (DMPK);
RNA, nucleus

affects processing of other gene RNA

Question 4

myotonic dystrophy:

severe forms come from ____ transmission. the largest expansions happen during _____ gametogenesis

Answer 4

maternal;

female

Question 5

myotonic dystropphy:

other genes have involvement. thus, data supports a ____-Dominant RNA gain of negative function, aka called ____ RNA

Answer 5

trans;

toxic

Question 6

molecular diagnosis of myotonic dystrophy:

____ PCR, followed by ____ to confirm size expansion

Answer 6

triplet-primed;
southern-blot;

see ppt

Question 7

friedreich ataxia (FA):
___ _____ disease (inheritance);
due to repeat of ____;
repeat is in a (exon or intron?)

Answer 7

autosomal recessive;
GAA (think GAAit);
intron

Question 8

FA:
gene that is mutated?
causes a ____ in gene expression;
the protein normally produced binds what?

Answer 8

Frataxin;
reduction/decrease;
iron

Question 9

FA:
____ gait, frequent ____, nystagmus, dys____, ____ (endocrine disorder);
cause of death usually =

Answer 9

staggering, falling;
arthria;

diabetes mellitus;

hypertrophic cardiomyopathy

Question 10

FA:

example of an expanded ____ ____ Tract

Answer 10

poly amino-acid

Question 11

Huntington disease (HD):
____ ____ inheritance;
due to repeat of ____ on chromosome ____;

Answer 11

autosomal dominant;

CAG, 4

Question 12

HD:
gene involved = ____;
in translating or untranslating region?
causes ____ tract in the protein.

Answer 12

HTT (huntington);
translating
polyglutamine

Question 13

HD:
normal number of repeats is less than _____;
____ or more means the patient will develop the disease

Answer 13

27 (ie 26 or less);
40

36-39 = may develop symptoms

Question 14

HD: repeats tend to expand more when transmitted by _____;

most of juvenile cases are transmitted by the _____

Answer 14

males, father

Question 15

____ expansions are seen in diseases such as synpolydactyly. the expansions usually occur in _____ ____

Answer 15

poly-alanine (ie GCx);

transcription factors