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genetics

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asmi
Forum Hero

Topics: 1043
Posts: 4,609

03/13/04 - 12:37 AM

Give examples for each:

1. transition
2.transversion
3.missence mutation
4.frameshift mutation
5.large segment deletion
6. splice donor mutation
7. triplet repeat expansion

step1taker
Forum Senior

Topics: 2
Posts: 105

03/13/04 - 01:27 PM

[quote="asmi"]Give examples for each:

1. transition - Purine for a purine (G for A), Pyrimidine for pyrimidine (C for U)

2.transversion - Purine for pyrimidine & vice versa

3.missence mutation - Valine for Glutamate in HbS

4.frameshift mutation- Duchennes dystrophy

5.large segment deletion - Alpha Thalassemia, Criduchat

6. splice donor mutation - Tay Sachs, Beta Thalassemia, Gauchers

7. triplet repeat expansion - fragile X(CGG),Huntington(CAG),Myotonic and spinobulbar dystrophies
:wink:

asmi
Forum Hero

Topics: 1043
Posts: 4,609

03/13/04 - 01:43 PM

thnx..

and example of drugs causing transitions....5 -FU
for tansversion......alkylating agents

myotonic dystrophy shows CTG repeats.

peekay
Forum Guru

Topics: 102
Posts: 588

03/13/04 - 04:04 PM

MY GENETICS IS NOT GOOD , I HAVE TO ADMIT THAT.MY QUESTION IS NOW ABOUT FRAME SHIFT . DO WE SEE FRAME SHIFT MUTATION OF PURINE AND PYRIMIDINE BASES.OR FRAME SHIFT MUTATION IS COMPLETELY DIFFERENT CONCEPT.
I WAY APPRECIATE IF SOME ONE CAN HELP ME UNDERSTAND GENETICS IN SHORT TIME OR ANYSNY SUGGESTION HOW TO GET READY FOR IT WITH OUT HAVING ANXIETY ATTACK.

asmi
Forum Hero

Topics: 1043
Posts: 4,609

03/13/04 - 04:22 PM

http://www.geneclinics.org/servlet/access?qry=ALL...

asmi
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03/13/04 - 04:24 PM

frameshift mutation: (synonyms: out-of-frame deletion, out-of-frame mutation) An insertion or deletion involving a number of base pairs that is not a multiple of three and consequently disrupts the triplet reading frame, usually leading to the creation of a premature termination (stop) codon and resulting in a truncated protein product

step1taker
Forum Senior

Topics: 2
Posts: 105

03/13/04 - 04:27 PM

"peekay" wrote:
MY GENETICS IS NOT GOOD , I HAVE TO ADMIT THAT.MY QUESTION IS NOW ABOUT FRAME SHIFT . DO WE SEE FRAME SHIFT MUTATION OF PURINE AND PYRIMIDINE BASES.OR FRAME SHIFT MUTATION IS COMPLETELY DIFFERENT CONCEPT.
I WAY APPRECIATE IF SOME ONE CAN HELP ME UNDERSTAND GENETICS IN SHORT TIME OR ANYSNY SUGGESTION HOW TO GET READY FOR IT WITH OUT HAVING ANXIETY ATTACK.

FRAMESHIFT MUTATION: simply means that amino acids (not in multiples of 3 ), were deleted causing misreading.
ex: CTG CAA GTC CTG
if 2 consecutive amino acids CA were removed, it will become:
CTG AGT CCT G
notice that the 2nd codon originally CAA became AGT.hence this is a Frameshift mutation.example of this is Duchenne's Dystropy. (severe type of muscle dystrophy)

it would be adifferent story if mutiples of 3 were deleted, using the same example; if entire codon CAA were deleted, it wil be read as
CTG GTC CTG
notice that its still thesame codons as the original but with the 2nd original codon deleted.Ths is an In FRAME mutaion.(ex: Becker's dystrophy-which is a milder form of dystrophy.)

I hope i was able to answer ur q.
Yeah, i know how u feel.Genetics is really intimidating.
But we really have to deal with it.God bless us :lol:

asmi
Forum Hero

Topics: 1043
Posts: 4,609

03/13/04 - 04:31 PM

that was a nice explanation ..

keep it up :idea:

peekay
Forum Guru

Topics: 102
Posts: 588

03/13/04 - 04:45 PM

THHANK YOU GUYS. I WILL UNDERSTAND THAT EXAMPLE AND CHECK THAT SITE AS WELL.

usmleasr
Forum Guru

Topics: 105
Posts: 970

03/13/04 - 08:28 PM

#10

good list of eg..thanks step1taker

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