Deck 45: Newborn Screening and Inborn Errors of Metabolism

Question 1

An autosomal recessive disorder:

A) is characterized by a 50% chance of an individual having the disease phenotype if the parents are heterozygous for the trait.
B) is defined as one in which there is a mutation in both alleles encoding for a specific enzyme/transporter.
C) affects males approximately 25% more than females because the allele is present on the X chromosome.
D) is one in which parents of diseased offspring are carriers of the condition in that they carry two mutant alleles.

Answer 1

is defined as one in which there is a mutation in both alleles encoding for a specific enzyme/transporter.

Question 2

A newborn screening test using a dried blood spot is positive for congenital adrenal hyperplasia (CAH).What laboratory testing would be done next?

A) No next step as this test is the confirmatory analysis
B) DNA analysis of genetic mutation
C) A stimulating hormone test
D) A second-tier test for CAH,such as an MS/MS steroid profile

Answer 2

A second-tier test for CAH,such as an MS/MS steroid profile

Question 3

Of the following,what is the inborn error of metabolism for medium chain acyl-CoA dehydrogenase deficiency?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Answer 3

Disorder of fatty acid oxidation

Question 4

Of the following,what is the inborn error of metabolism for glycogen storage disease?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Question 5

Of the following,what is the inborn error of metabolism for glutaric acidemia type 1?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Question 6

Of the following,what is the inborn error of metabolism for maple syrup urine disease?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Question 7

Of the following,what is the inborn error of metabolism for alkaptonuria?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Question 8

Newborn screening is considered a public health activity that aims to identify and treat possible deadly conditions early in an infant's life.Which one of the following characteristics must be met before a disease can be part of a screening program?

A) The disease must be rare.
B) Genetic counseling and treatment for the disease must be available.
C) The natural history of the disease must be unclear.
D) Screening for the disease must only be offered to those who would benefit most from it.

Question 9

Of the following,what is the inborn error of metabolism for propionic acidemia?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Disorder of carbohydrate metabolism

Question 10

Hyperphenylalaninemia due to classic phenylketonuria (PKU)is accompanied by all the following except:

A) elevation of blood tyrosine.
B) elevation in urinary phenylketones.
C) elevation in blood phenylalanine correctable by dietary phenylalanine restriction.
D) mental retardation if left untreated.

Question 11

The disorder that is identified by increased serum carnitine and urine glutaric acid on newborn screening is characterized by dysfunctional metabolism of:

A) hydroxylysine and phenylalanine.
B) tyrosine and tryptophan.
C) tryptophan,hydroxylysine,and lysine.
D) cystine and hydroxylysine.

Question 12

The disorder that is identified by increased serum carnitine and urine glutaric acid on newborn screening is:

A) PKU.
B) tyrosinemia.
C) glutaric acidemia type 1.
D) glycine encephalopathy.

Question 13

An example of a confirmatory laboratory test used to verify a borderline abnormal newborn screening test result in an asymptomatic individual would be gas chromatography combined with mass spectrometry,particularly for organic acid analysis.

Question 14

What is the basic setup of a tandem mass spectrometry analyzer?

A) Tandem mass spectrometry uses a UV laser to ionize small amounts of matrix and analyte that are directed toward mass analyzer.
B) Tandem mass spectrometry is primarily for complex compound analysis,while tandem mass spectrometry is used for elemental analysis only.
C) Tandem mass spectrometry uses an ion trap designed to trap ions in three dimensions instead of two dimensions as in a typical beam type of mass spectrometer.
D) Two beam type mass spectrometers are arranged sequentially in tandem mass spectrometry,with a "collision cell" placed between the two instruments.

Question 15

What is the advantage of tandem mass spectrometry (MS/MS)multiplex analysis?

A) It eliminates the need for second-tier testing by providing a built-in confirmatory test.
B) Multiple metabolites are detected simultaneously in one blood sample to allow for detection of several disorders at once.
C) Tests are performed singly so a single disorder is tested for with a single specimen.
D) It allows for screening of a large number of infants not only for PKU,but also for other disorders of amino acid metabolism using different growth antagonists.

Question 16

A newborn infant is observed to have symptoms of poor feeding,vomiting,lethargy,and irritability.Screening tests reveal elevated ornithine and ammonia in the infant's blood.What type of disorder do these symptoms indicate?

A) Disorder of fatty acid oxidation
B) Aminoacidopathy
C) Organic acidemia
D) Urea cycle disorder

Question 17

Dietary restriction of foods containing the branched-chain amino acids is one of the treatments required for individuals with:

A) phenylketonuria.
B) glutaric acidemia type 1.
C) maple syrup urine disease.
D) alkaptonuria.