mucopolysaccharidosis Type II & genetics - USMLE Forums
 USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
 Home USMLE Articles USMLE News USMLE Polls USMLE Books USMLE Apps
 USMLE Forums mucopolysaccharidosis Type II & genetics
 User Name Remember Me? Password
 Register FAQs Members List Search Today's Posts Mark Forums Read

 USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam

 Thread Tools Search this Thread Display Modes
#1
05-30-2011
 USMLE Forums Addict Steps History: 1 + CS Posts: 113 Threads: 8 Thanked 89 Times in 61 Posts Reputation: 99
mucopolysaccharidosis Type II & genetics

Hunter syndrome, or mucopolysaccharidosis Type II, is a rare disease that it shows X-linked recessive inheritance. In a female with 2 brothers with the diasese, which of the following is correct?

a) The probability that she is a carrier is 2/3.
b) If she is a carrier then the probability that each of her sons will be affected is 1 in 4.
c) If she is a carrier then the probability that each of her daughters will be a carrier is 1 in 4.
d) Before any carrier testing is carried out the woman can be correctly informed that the probability that her first son will be affected is 1 in 4.
 The above post was thanked by: apx85 (05-30-2011), usluipek (05-30-2011)

#2
05-30-2011
 USMLE Forums Master Steps History: 1+CK+CS+3 Posts: 1,357 Threads: 194 Thanked 3,269 Times in 881 Posts Reputation: 3279

no idea which one is the right answer...

the probability that her son will be affected is 1 in 2
the probability that her daughter will be carrier is 1 in 2
#3
05-30-2011
 USMLE Forums Master Steps History: 1+CK+CS+3 Posts: 1,175 Threads: 38 Thanked 854 Times in 478 Posts Reputation: 864

Im stuck between A) and C)

What's with the recent flux of genetics questions?

#4
05-30-2011
 USMLE Forums Guru Steps History: --- Posts: 332 Threads: 48 Thanked 170 Times in 109 Posts

Pls keep genetic calculation coming, the more the better!
#5
05-30-2011
 USMLE Forums Newbie Steps History: Step 1 Only Posts: 5 Threads: 2 Thanked 16 Times in 3 Posts Reputation: 26

a) The probability that she is a carrier is 2/3.---should be 1/2
b) If she is a carrier then the probability that each of her sons will be affected is 1 in 4.---if she's a carrier, Xx, then son will be 1/2 chance to have dz
c) If she is a carrier then the probability that each of her daughters will be a carrier is 1 in 4.--daughter would be 1/2 carrier
d) Before any carrier testing is carried out the woman can be correctly informed that the probability that her first son will be affected is 1 in 4.--this one is right. possibility to be a carrier 1/2, transfer the bad one to don is 1/2, so 1/2*1/2=1/4
 The above post was thanked by: apx85 (05-30-2011), bebix (05-30-2011), kiki (05-31-2011), struggle (05-30-2011), usluipek (05-30-2011)
#6
05-30-2011
 USMLE Forums Master Steps History: 1+CK+CS+3 Posts: 1,357 Threads: 194 Thanked 3,269 Times in 881 Posts Reputation: 3279

Quote:
 Originally Posted by 123to789 a) The probability that she is a carrier is 2/3.---should be 1/2 b) If she is a carrier then the probability that each of her sons will be affected is 1 in 4.---if she's a carrier, Xx, then son will be 1/2 chance to have dz c) If she is a carrier then the probability that each of her daughters will be a carrier is 1 in 4.--daughter would be 1/2 carrier d) Before any carrier testing is carried out the woman can be correctly informed that the probability that her first son will be affected is 1 in 4.--this one is right. possibility to be a carrier 1/2, transfer the bad one to don is 1/2, so 1/2*1/2=1/4
you´re absolutely right. Thanks!
 The above post was thanked by: leo lakhani (05-30-2011)

 Tags Biochemistry-, Genetics-, Syndromes-Acronyms

Quick Reply
Message:
Options

## Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
 Please enter a password for your user account. Note that passwords are case-sensitive. Password: Confirm Password:
Email Address
 Please enter a valid email address for yourself. Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
 AMG IMG ---
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

 Not yet Step 1 Only CK Only CS Only 1 + CK 1 + CS 1+CK+CS CK+CS 1+CK+CS+3 ---
Favorite USMLE Books
 What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
 Where you live. Leave blank if you don't want to tell.

## Log-in

 User Name Remember Me? Password
Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

 Thread Tools Search this Thread Search this Thread: Advanced Search Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Claus_CU USMLE Step 1 Forum 22 02-20-2015 11:19 AM wasify81 USMLE Step 1 Forum 0 12-04-2010 10:05 AM lee-usmle USMLE Step 1 Mnemonics 1 12-16-2009 10:17 AM Dr. N Elham USMLE Step 1 Forum 3 12-07-2009 06:45 PM US-Colar USMLE Step 1 Forum 2 10-19-2009 10:27 AM

 Home - Contact Us - Forum Rules - Advertise - Mobile Site - Archive - Privacy Statement - Top
 Follow @usmleforums
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)

 Terms of Use