MGY 250 ALL UNITS EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE
2025/2026
RB1 Genetics - Answers Autosomal dominant disease
Two hotspot mutations, but can mutate it infinitely many ways
Deletion of large sections = fewer RB, since you require second allele copy to show the stronger
mutation
Know how the retinoblastoma phenotypes relates to RB1 genetics - Answers - All bilateral +
some unilateral carry mutant RB1 in germline (heritable)
- Most unilateral have both RB1 alleles absent or MYCNamp amplified
Non heritable retinoblastoma tumors are - Answers Identical
Define bilateral - Answers Tumor in both eyes
Define unilateral - Answers Tumor in one eye
Define M1 and M2 mutation - Answers M1 mutation: Primary mutation causing +/-
M2 mutation: Secondary mutation causing -/-
How was the physical location of RB1 determined - Answers - Chromosome 13: patients with
big deletions had high risk of retinoblastoma
- Five probes that might be deleted in tumor, found one H38: no band found in Southern blot
- Pulled RNA transcript and found RB1 gene
Importance of early retinoblastoma detection in Kenya - Answers Late diagnosis may result in
need for chemotherapy, expensive drugs and overcrowded radiotherapy lists
Challenge to treating RB in Kenya - Answers Late diagnosis, no genetic testing, limited genetic
counselling
3 facets of providing retinoblastoma medical care according to Dr. Kahaki - Answers Tests
confirming diagnosis
Tests confirming diseases extent
Providing appropriate treatment
Why is there a global disparity in retinoblastoma survival - Answers Most RB occurs in low
resource settings, cannot treat them properly
Barriers to uptake of genetic information - Answers 1. Messenger: nurse/doctor/genetic
,counselor training
2. Message: different based on genetic testing availability
3. Barriers: Sociocultural and/or psychosocial
What are the 3 pillars of comprehensive genetics services and how do they apply - Answers
Medical Education, Community Engagement, Patient and Family Counselling
Patient and Family Counselling - Answers Conflict with traditional beliefs, thus conduct focus
groups and involve traditional healers
Medical Education - Answers Develop training curriculum and use workshops to test knowledge
retention, as well as scholar programs
Community Engagement - Answers - New Kenyan Community Health Worker (CHW), 1 per 20
families, can disseminate genetic information
- Support mother's decisions and engage families
What is integrated knowledge translation and why is it being used to address barriers to
retinoblastoma treatment - Answers Involves variety of stakeholders to design research
objectives and methodology to help patient experience.
Collaboration can help drive relevant research towards patients to be implemented in long run
Stakeholders of Integrated Knowledge transition - Answers Clinical/Research teams,
Families/survivors, advocates
How does retinoblastoma care vary worldwide - Answers Large amount of low resourced
settings with unavailable help
Different types of results that can be received from genetic testing - Answers 1. Pathogenic
results
2. Secondary finding
3. Variant of Unknown clinical Significance (VUS)
4. Negative results
Genetic Testing Result: Pathogenic result - Answers Sequence change in gene causative of
phenotype, has implications for family members
Gene Testing Result: Secondary finding - Answers Only reveal medically actionable, can reveal
child or adult onset disease, has implications for family members
Gene Testing Result: Variant of Unknown clinical Significance (VUS) - Answers Cannot be
, interpreted accurately and can't be ruled out as benign or pathogenic
Gene Testing Result: Negative result - Answers Ideally disease free, but not necessarily
Define medically actionable - Answers Some action can be taken for an individual to prevent or
alter a genetic disease
Criteria for judging whether a variant of unknown clinical significance is benign or pathogenic -
Answers 1. 1000 Genomes Frequency
2. Inheritance pattern (de novo vs mutation)
3. Report in literature
4. Conservation of mutated position across species
5. Effect of mutation on protein structure
Reasons why an individual would go see a genetic counsellor - Answers 1. Parents who have
just had a baby with birth defects
2. Parents of a boy diagnosed with Duchenne
3. Family history of genetic condition
4. First cousin couple
5. Repeated pregnancy losses
6. Adolescents with pre-existing defect
Pros of identifying medically actionable secondary findings of adult onset disease in paediatric
cases - Answers - Informed future planning, including new interventions, lifestyle changes,
preparation
- Promotes autonomy
- Parents should have right to decide their child's best interests
- Facilitates openness in family
- Improve health of family members
Cons of identifying medically actionable secondary findings of adult onset disease in paediatric
cases - Answers - Loss of open future
- Loss privacy
- Not respect developing autonomy of child
2025/2026
RB1 Genetics - Answers Autosomal dominant disease
Two hotspot mutations, but can mutate it infinitely many ways
Deletion of large sections = fewer RB, since you require second allele copy to show the stronger
mutation
Know how the retinoblastoma phenotypes relates to RB1 genetics - Answers - All bilateral +
some unilateral carry mutant RB1 in germline (heritable)
- Most unilateral have both RB1 alleles absent or MYCNamp amplified
Non heritable retinoblastoma tumors are - Answers Identical
Define bilateral - Answers Tumor in both eyes
Define unilateral - Answers Tumor in one eye
Define M1 and M2 mutation - Answers M1 mutation: Primary mutation causing +/-
M2 mutation: Secondary mutation causing -/-
How was the physical location of RB1 determined - Answers - Chromosome 13: patients with
big deletions had high risk of retinoblastoma
- Five probes that might be deleted in tumor, found one H38: no band found in Southern blot
- Pulled RNA transcript and found RB1 gene
Importance of early retinoblastoma detection in Kenya - Answers Late diagnosis may result in
need for chemotherapy, expensive drugs and overcrowded radiotherapy lists
Challenge to treating RB in Kenya - Answers Late diagnosis, no genetic testing, limited genetic
counselling
3 facets of providing retinoblastoma medical care according to Dr. Kahaki - Answers Tests
confirming diagnosis
Tests confirming diseases extent
Providing appropriate treatment
Why is there a global disparity in retinoblastoma survival - Answers Most RB occurs in low
resource settings, cannot treat them properly
Barriers to uptake of genetic information - Answers 1. Messenger: nurse/doctor/genetic
,counselor training
2. Message: different based on genetic testing availability
3. Barriers: Sociocultural and/or psychosocial
What are the 3 pillars of comprehensive genetics services and how do they apply - Answers
Medical Education, Community Engagement, Patient and Family Counselling
Patient and Family Counselling - Answers Conflict with traditional beliefs, thus conduct focus
groups and involve traditional healers
Medical Education - Answers Develop training curriculum and use workshops to test knowledge
retention, as well as scholar programs
Community Engagement - Answers - New Kenyan Community Health Worker (CHW), 1 per 20
families, can disseminate genetic information
- Support mother's decisions and engage families
What is integrated knowledge translation and why is it being used to address barriers to
retinoblastoma treatment - Answers Involves variety of stakeholders to design research
objectives and methodology to help patient experience.
Collaboration can help drive relevant research towards patients to be implemented in long run
Stakeholders of Integrated Knowledge transition - Answers Clinical/Research teams,
Families/survivors, advocates
How does retinoblastoma care vary worldwide - Answers Large amount of low resourced
settings with unavailable help
Different types of results that can be received from genetic testing - Answers 1. Pathogenic
results
2. Secondary finding
3. Variant of Unknown clinical Significance (VUS)
4. Negative results
Genetic Testing Result: Pathogenic result - Answers Sequence change in gene causative of
phenotype, has implications for family members
Gene Testing Result: Secondary finding - Answers Only reveal medically actionable, can reveal
child or adult onset disease, has implications for family members
Gene Testing Result: Variant of Unknown clinical Significance (VUS) - Answers Cannot be
, interpreted accurately and can't be ruled out as benign or pathogenic
Gene Testing Result: Negative result - Answers Ideally disease free, but not necessarily
Define medically actionable - Answers Some action can be taken for an individual to prevent or
alter a genetic disease
Criteria for judging whether a variant of unknown clinical significance is benign or pathogenic -
Answers 1. 1000 Genomes Frequency
2. Inheritance pattern (de novo vs mutation)
3. Report in literature
4. Conservation of mutated position across species
5. Effect of mutation on protein structure
Reasons why an individual would go see a genetic counsellor - Answers 1. Parents who have
just had a baby with birth defects
2. Parents of a boy diagnosed with Duchenne
3. Family history of genetic condition
4. First cousin couple
5. Repeated pregnancy losses
6. Adolescents with pre-existing defect
Pros of identifying medically actionable secondary findings of adult onset disease in paediatric
cases - Answers - Informed future planning, including new interventions, lifestyle changes,
preparation
- Promotes autonomy
- Parents should have right to decide their child's best interests
- Facilitates openness in family
- Improve health of family members
Cons of identifying medically actionable secondary findings of adult onset disease in paediatric
cases - Answers - Loss of open future
- Loss privacy
- Not respect developing autonomy of child
