B-Thallessemia

Prep for USMLE Forum

» Log in | Register

Forum

Step 1

Match

Prep4USMLE Forum » USMLE Step 1 Forum » Biochemistry Forum

B-Thallessemia

Author

14 Posts

MLF
Forum Elite

Topics: 36
Posts: 386

09/25/04 - 11:47 AM

What kind of mutation is found in Beta Thallessemia????

___________________
"Support bacteria, its the only culture some people got."

meghana jadhav
Forum Elite

Topics: 80
Posts: 304

09/25/04 - 12:22 PM

b thalassemia......caused by mutations in the HBB gene....
Most of the mutations are changes in single nucleotides in the sequence of DNA in the HBB gene.either by insertion or delesion of the ...nucleotide in the hbb gene...

___________________
megha

MLF
Forum Elite

Topics: 36
Posts: 386

09/25/04 - 01:14 PM

so no frameshift, reason i am asking is because a question similar to this was on my friend's step 1, and they chose frameshift.....

___________________
"Support bacteria, its the only culture some people got."

Sakaki-
Forum Senior

Topics: 1
Posts: 238

09/25/04 - 01:57 PM

As meghana jadhav stated, most of the genetic defects are caused by point mutations.

mjl1717
Forum Hero
avatar

Topics: 958
Posts: 5,465

09/25/04 - 02:25 PM

If it was alpha thal.-- the answer would be large segent deletion(unequal crossing over in meiosis)

___________________
Smell the coffee! "Is That an Osler move??"

Malaysian
Forum Guru

Topics: 28
Posts: 778

09/29/04 - 11:14 AM

I read somewhere that spliceosome defect can lead to mutation of beta thallasemia,unfortunately I can't confirm......

polkos
Forum Senior

Topics: 7
Posts: 88

09/29/04 - 01:13 PM

in beta thal the mutations in splice sites are responsible....as per kaplan biochem.

polkos
Forum Senior

Topics: 7
Posts: 88

09/29/04 - 01:13 PM

in beta thal the mutations in splice sites are responsible....as per kaplan biochem.

MLF
Forum Elite

Topics: 36
Posts: 386

10/02/04 - 07:06 PM

According to goljan:
beta = Point mutation produces a splicing defect, resulting in a decrease in Beta chains on Ch11
Alpha = Gene deletion on ch 16

Now can anyone tell me levels of HbA, HbA2, and HbF in both of these defects?

___________________
"Support bacteria, its the only culture some people got."

sofianee
Forum Junior

Topics: 3
Posts: 41

10/03/04 - 02:47 PM

#10

B thal: HbA (Decreased) HbA2 and HbF (increased)
A thal: HbA, HbA2 and HbF (all decreased)

By the way B thal is a point mutation on the Chr 11 (6th aa: Valine instead of glutamic acid)

sofianee
Forum Junior

Topics: 3
Posts: 41

10/03/04 - 02:48 PM

#11

B thal: HbA (Decreased) HbA2 and HbF (increased)
A thal: HbA, HbA2 and HbF (all decreased)

By the way B thal is a point mutation on the Chr 11 (6th aa: Valine instead of glutamic acid)

MLF
Forum Elite

Topics: 36
Posts: 386

10/03/04 - 03:26 PM

#12

good!!!!!

___________________
"Support bacteria, its the only culture some people got."

mani
Forum Guru
avatar

Topics: 104
Posts: 1,403

10/03/04 - 04:12 PM

#13

"sofianee" wrote:
By the way B thal is a point mutation on the Chr 11 (6th aa: Valine instead of glutamic acid)

i disagree with u sofianee, perhaps u r talking about sickle cell dis mutation

___________________
Sincerity and hard work are the keys to success!

mjl1717
Forum Hero
avatar

Topics: 958
Posts: 5,465

10/03/04 - 08:09 PM

#14

I agree with Mani---6th position of Beta chain-valine for glutamic acid
is sickle cell anemia--severity related to amount of Hemoglobin S and O2 content

___________________
Smell the coffee! "Is That an Osler move??"

You don't have permission to post.