Author Question: The nurse is assessing the knowledge of new parents with a child born with maple syrup urine disease ... (Read 97 times)

mydiamond · **on:** Jun 28, 2018

The nurse is assessing the knowledge of new parents with a child born with maple syrup urine disease (MSUD). This is an autosomal recessive inherited disorder, which means that:

a. Both genes of a pair must be abnormal for the disorder to be expressed.
b. Only one copy of the abnormal gene is required for the disorder to be expressed.
c. The disorder occurs in males and heterozygous females.
d. The disorder is carried on the X chromosome.

Question 2

A man's wife is pregnant for the third time. One child was born with cystic fibrosis, and the other child is healthy. The man wonders what the chance is that this child will have cystic fibrosis. This type of testing is known as:

a. Occurrence risk. c. Predictive testing.
b. Recurrence risk. d. Predisposition testing.

juwms · **Reply #1 on:** Jun 28, 2018

Answer to Question 1

ANS: A
MSUD is a type of autosomal recessive inheritance disorder in which both genes of a pair must be abnormal for the disorder to be expressed. MSUD is not an X-linked dominant or recessive disorder or an autosomal dominant inheritance disorder.

Answer to Question 2

ANS: B
The couple already has a child with a genetic disease so they will be given a recurrence risk test. If a couple has not yet had children but are known to be at risk for having children with a genetic disease, they are given an occurrence risk test. Predictive testing is used to clarify the genetic status of an asymptomatic family member. Predisposition testing differs from presymptomatic testing in that a positive result does not indicate 100 risk of a condition developing.