ROBBINS BASIC PATHOLOGY
10TH EDITION
AUTHOR(S)VINAY KUMAR; ABUL K.
ABBAS; JON C. ASTER
TEST BANK
Reference – Ch. 1 — The Genome
Question Stem
A 32-year-old pregnant patient is found on prenatal screening
to carry a balanced reciprocal translocation but is
phenotypically normal. Which clinical counseling point best
explains the genomic risk relevant to future offspring?
Options
A. Balanced translocations always produce affected offspring
due to gene disruption.
B. The parent’s balanced translocation increases risk for
gametes with unbalanced chromosomal complements.
C. Balanced translocations are eliminated during gametogenesis
and pose no reproductive risk.
,D. Balanced translocations convert into point mutations in
offspring and cause single-gene disorders.
Correct Answer
B
Rationales
Correct: Balanced reciprocal translocations preserve gene
dosage in the carrier but can lead to abnormal segregation
during meiosis, producing gametes with unbalanced
chromosomal content and resulting phenotypically abnormal
offspring or recurrent pregnancy loss.
A (incorrect): Balanced carriers are usually phenotypically
normal; they do not always produce affected offspring.
C (incorrect): They are not eliminated during gametogenesis;
segregation patterns determine risk.
D (incorrect): Translocations do not “convert” into point
mutations; they affect chromosomal structure and dosage, not
single-nucleotide changes.
Teaching Point
Balanced translocations risk unbalanced gametes → possible
affected offspring or miscarriage.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2.
Reference – Ch. 1 — The Genome
,Question Stem
A patient presents with progressive muscle weakness and
diagnostic testing reveals trinucleotide repeat expansion in a
gene. Which pathobiologic mechanism best explains
anticipation in such disorders?
Options
A. Environmental mutagens increase repeat length only in
somatic cells.
B. Repeat expansions tend to increase in size during
gametogenesis, producing earlier/severe disease in successive
generations.
C. DNA polymerase proofreading eliminates repeats in
successive generations, reducing severity.
D. Repeat expansions solely affect mitochondrial DNA and
maternal inheritance.
Correct Answer
B
Rationales
Correct: Trinucleotide repeats can expand during germline
replication, particularly in spermatogenesis or oogenesis
depending on the disorder, causing earlier onset or more severe
disease (anticipation) in subsequent generations.
A (incorrect): While mutagens can cause mutations, anticipation
is due to germline repeat expansion, not somatic-only changes.
C (incorrect): DNA polymerase proofreading does not reliably
correct repeat expansions and, in fact, replication slippage
, increases them.
D (incorrect): Trinucleotide repeats are nuclear DNA
phenomena; they are not confined to mitochondrial DNA.
Teaching Point
Trinucleotide repeat expansions can grow during
gametogenesis, causing anticipation.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3.
Reference – Ch. 1 — The Genome
Question Stem
A young adult’s tumor sequencing shows loss of heterozygosity
(LOH) at a tumor suppressor locus. How does LOH contribute to
tumorigenesis?
Options
A. LOH amplifies oncogene expression through gene
duplication.
B. LOH removes the remaining functional allele of a tumor
suppressor, enabling malignant transformation.
C. LOH increases DNA repair capacity and prevents mutation
accumulation.
D. LOH converts tumor suppressor genes into oncogenes via
point mutation.
10TH EDITION
AUTHOR(S)VINAY KUMAR; ABUL K.
ABBAS; JON C. ASTER
TEST BANK
Reference – Ch. 1 — The Genome
Question Stem
A 32-year-old pregnant patient is found on prenatal screening
to carry a balanced reciprocal translocation but is
phenotypically normal. Which clinical counseling point best
explains the genomic risk relevant to future offspring?
Options
A. Balanced translocations always produce affected offspring
due to gene disruption.
B. The parent’s balanced translocation increases risk for
gametes with unbalanced chromosomal complements.
C. Balanced translocations are eliminated during gametogenesis
and pose no reproductive risk.
,D. Balanced translocations convert into point mutations in
offspring and cause single-gene disorders.
Correct Answer
B
Rationales
Correct: Balanced reciprocal translocations preserve gene
dosage in the carrier but can lead to abnormal segregation
during meiosis, producing gametes with unbalanced
chromosomal content and resulting phenotypically abnormal
offspring or recurrent pregnancy loss.
A (incorrect): Balanced carriers are usually phenotypically
normal; they do not always produce affected offspring.
C (incorrect): They are not eliminated during gametogenesis;
segregation patterns determine risk.
D (incorrect): Translocations do not “convert” into point
mutations; they affect chromosomal structure and dosage, not
single-nucleotide changes.
Teaching Point
Balanced translocations risk unbalanced gametes → possible
affected offspring or miscarriage.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2.
Reference – Ch. 1 — The Genome
,Question Stem
A patient presents with progressive muscle weakness and
diagnostic testing reveals trinucleotide repeat expansion in a
gene. Which pathobiologic mechanism best explains
anticipation in such disorders?
Options
A. Environmental mutagens increase repeat length only in
somatic cells.
B. Repeat expansions tend to increase in size during
gametogenesis, producing earlier/severe disease in successive
generations.
C. DNA polymerase proofreading eliminates repeats in
successive generations, reducing severity.
D. Repeat expansions solely affect mitochondrial DNA and
maternal inheritance.
Correct Answer
B
Rationales
Correct: Trinucleotide repeats can expand during germline
replication, particularly in spermatogenesis or oogenesis
depending on the disorder, causing earlier onset or more severe
disease (anticipation) in subsequent generations.
A (incorrect): While mutagens can cause mutations, anticipation
is due to germline repeat expansion, not somatic-only changes.
C (incorrect): DNA polymerase proofreading does not reliably
correct repeat expansions and, in fact, replication slippage
, increases them.
D (incorrect): Trinucleotide repeats are nuclear DNA
phenomena; they are not confined to mitochondrial DNA.
Teaching Point
Trinucleotide repeat expansions can grow during
gametogenesis, causing anticipation.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3.
Reference – Ch. 1 — The Genome
Question Stem
A young adult’s tumor sequencing shows loss of heterozygosity
(LOH) at a tumor suppressor locus. How does LOH contribute to
tumorigenesis?
Options
A. LOH amplifies oncogene expression through gene
duplication.
B. LOH removes the remaining functional allele of a tumor
suppressor, enabling malignant transformation.
C. LOH increases DNA repair capacity and prevents mutation
accumulation.
D. LOH converts tumor suppressor genes into oncogenes via
point mutation.
