Deck 9: Common Childhood-Onset Genetic Disorders

Question 1

Which type of testing is most commonly used to diagnose cystic fibrosis?

A)Mucus protein electrophoresis
B)Genetic mutation analysis
C)Sweat chloride analysis
D)Stool analysis

Answer 1

Sweat chloride analysis

Question 2

Which tissues are most commonly affected by mutation of the CFTR gene?

A)Eyes and ears
B)Brain and intestines
C)Lungs and pancreas
D)Kidneys and long bones

Answer 2

Lungs and pancreas

Question 3

What health advantage does cystic fibrosis confer on the person who has it?

A)Decreased risk for type 1 diabetes mellitus
B)Decreased risk for tuberculosis
C)Decreased risk for anemia
D)Decreased risk for cholera

Answer 3

Decreased risk for cholera

Question 4

How is sickle cell trait different from sickle cell disease?

A)People with sickle cell disease are homologous for the mutation,whereas those with sickle cell trait are heterozygous for the mutation.
B)People with sickle cell trait are homologous for the mutation,whereas those with sickle cell disease are heterozygous for the mutation.
C)Sickle cell disease results from an inherited mutation,and sickle cell trait results from an acquired mutation.
D)Sickle cell trait results from an inherited mutation,and sickle cell disease results from an acquired mutation.

Question 5

How does hydroxyurea reduce the manifestations of sickle cell disease?

A)Promoting red blood cell production
B)Increasing the concentration of fetal hemoglobin (HbF)
C)Relaxing vascular smooth muscle so that blood flow to critical tissues and organs is improved
D)Correcting the mutation of one allele so the person has sickle cell trait instead of sickle cell disease

Question 6

Why does Duchenne muscular dystrophy (DMD)have poor reproductive fitness?

A)Most affected individuals typically do not have children.
B)Fifty percent of mutations of the dystrophin gene are deletions.
C)The loss of functional adhesion proteins prevents reproduction.
D)The expression of disease severity is highly variable among adults.

Question 7

Which type of testing is most commonly used to diagnose sickle cell disease?

A)Hematocrit and hemoglobin levels
B)Hemoglobin electrophoresis
C)Genetic mutation analysis
D)Sweat chloride analysis

Question 8

What is the most likely explanation for the variability in expression of disease severity for cystic fibrosis?

A)The ethnicity of the patient
B)The specific CFTR gene mutation inherited
C)The presence of other nongenetic lung or pancreatic problems
D)The length of trinucleotide repeat sequences in the first exon of the CFTR gene

Question 9

A woman whose hemoglobin S levels are less than 1% has a brother with sickle cell disease and both parents have been diagnosed as carriers for the disorder.She asks what her risks are of having a child with sickle cell disease.What is the best response?

A)"Because you do not have the trait,you cannot have a child with sickle cell disease regardless of your partner's sickle cell status."
B)"Because both your parents have the trait,it is possible for you to have a child with sickle cell disease if your partner actually has the disease."
C)"Because your brother actually has sickle cell disease,the risk for your children having sickle cell disease is 50% with each pregnancy."
D)"Because you are a woman,your daughters will each have a 50% risk for having the disease and all of your sons will be carriers of the trait."

Question 10

Which additional health problem commonly develops in boys with Duchenne muscular dystrophy?

A)Arthritis
B)Hypertension
C)Diabetes mellitus
D)Chronic heart failure

Question 11

Zoe,a 20-year-old woman,shows signs of mild muscle weakness.She has two first cousins on her mother's side who died of Duchenne's muscular dystrophy (DMD).Which explanation regarding Zoe's situation is most likely?

A)Zoe is a heterozygote showing partial expression.
B)Zoe and her cousins shared similar environmental risks.
C)The muscle weakness is related to Zoe's lack of exercise in her "girly-girl" lifestyle.
D)Zoe is homozygous for DMD,with a defective dystrophin gene inherited from both parents.

Question 12

What is the explanation for creatine kinase (CK)levels in a 14-year-old boy with Duchenne muscular dystrophy being much lower now than they were 5 years ago?

A)His disease is improving.
B)He now performs passive rather than active exercise.
C)Most of the muscle tissue has already been destroyed.
D)The disease is probably Becker muscular dystrophy rather than Duchenne muscular dystrophy.

Question 13

Which relative of a patient who has cystic fibrosis has the correct risk for being a cystic fibrosis carrier?

A)Sister 0%
B)Mother 50%
C)Father 100%
D)Brother 100%

Question 14

Which common childhood disorder requires a genetic contribution and a significant environmental contribution to develop fully?

A)Achondroplasia
B)Sickle cell disease
C)Type 1 diabetes mellitus
D)von Willebrand disease

Question 15

Which statement regarding classic hemophilia is true?

A)Females are not affected.
B)Because hemophilia is X-linked recessive,females are affected and males are carriers.
C)Because hemophilia is X-linked recessive,males are affected and females are carriers.
D)The sons of women who are older than age 40 when pregnant are at an increased risk for hemophilia.

Question 16

Which ethnic group has the highest incidence of sickle cell disease?

A)Ashkenazi Jews
B)Asian Americans
C)African Americans
D)French Canadians from Quebec

Question 17

Which specific type of genetic problem causes sickle cell disease?

A)Deletion of an exon
B)Deletion of an intron
C)Unbalanced translocation
D)Single nucleotide polymorphism

Question 18

A 21-year-old woman who has two brothers with Duchenne muscular dystrophy asks whether carrier status testing is appropriate for her.What is the best response?

A)"Testing could be beneficial because your risk for being a carrier is nearly 100%."
B)"Testing could be beneficial because your risk for being a carrier is approximately 50%.
C)"Testing is not necessary because you would have expressed some symptoms of the disease by this time if you were a carrier."
D)"Testing is not necessary because the spontaneous mutation rate for this genetic problem is high and likely to be why your brothers have the disease."

Question 19

Which ethnic group has the highest incidence of cystic fibrosis?

A)Asian Americans
B)African Americans
C)Hispanic Americans
D)European Americans

Question 20

What health advantage does sickle cell trait or disease confer on the person who has it?

A)Decreased risk for type 1 diabetes mellitus
B)Decreased risk for hypercholesterolemia
C)Decreased risk for fulminating cholera
D)Decreased risk for malaria

Question 21

Which phenotypic feature associated with achondroplasia has variable expression?

A)Disproportionally short extremities
B)Larger than average head size
C)Prominent forehead
D)Hydrocephaly

Question 22

A son with achondroplasia is born to parents with no family history of the disease.What is the most likely explanation for the son's disorder?

A)The son is not biologically related to the father.
B)The son is not biologically related to the mother.
C)The gamete of one parent had a spontaneous mutation.
D)The son's DNA underwent a spontaneous mutation during the second trimester of pregnancy.

Question 23

Which result of genetic/genomic variation has the most support as a cause of asthma?

A)Decreased resistance to infectious microorganisms
B)Early childhood exposures to inhalation irritants (air pollution)
C)Increased inflammatory responses to environmental triggers
D)Mutations of frontal lobe genes controlling attention-getting behavior

Question 24

Which factor has the greatest influence in the development of type 1 diabetes mellitus?

A)Inheritance of the HLA-DR or HLA-DQ tissue types
B)Sedentary lifestyle coupled with childhood obesity
C)Mutation in the gene for pancreas development
D)Advanced maternal age at conception

Question 25

Which statement regarding type 1 von Willebrand disease (VWD)is true?

A)Incomplete or reduced penetrance is common.
B)It represents a female form of classic hemophilia.
C)Carriers can transmit the disease to their children.
D)Males are affected twice as frequently as females

Question 26

Which type of testing is most commonly used to diagnose classic hemophilia?

A)Hematocrit and hemoglobin levels
B)X-chromosome inactivation
C)Genetic mutation analysis
D)Factor VIII levels

Question 27

Which type of gene could be considered a "candidate gene" for mutations that increase the genetic input to asthma development?

A)One that controls the expression of hemoglobin levels
B)One that regulates the number of alveoli a person develops
C)One that regulates the sensitivity of bronchiolar smooth muscle
D)One that is responsible for the metabolism and elimination of nicotine