MGY250 UNIT 5 - COMPLEX DISORDERS
EXAM QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
Define case - ANS Affected individuals
Define controls - ANS Non-affected individuals
Case control studies - ANS Pair affected individuals with non-affected, matched according to
environment exposure, occupation, geographical location. Ideally only difference should be
disease presence. Compare extended families of both affected/non affected
Odds ratio - ANS Odds individual with a specific variant develops disease
Odds ratio calculation - ANS Ratio between
= odds of being affected with variant present : odds of being affected with NO variant present
Odds of being affected with variant present calculation - ANS Number of cases with variant /
Number of controls with variant
High odds ratio indicates.. - ANS very likely that the variant's presence indicates disease
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Sources of bias in twin studies - ANS Shared environment for siblings
Ascertainment bias
Recall bias
Odds of being affected with NO variant present calculation - ANS Number of cases without
variant / Number of controls without variant
Shared environment for siblings - ANS May lead to overestimate of heritability of trait
Ascertainment bias - ANS Families with more than one affected sibling are more likely to
come under attention of researcher
Recall bias - ANS Unrealistic to examine all relatives directly, may have to rely on anecdotal
memories
Purpose and utility of whole genome sequencing - ANS WGS provides full information
regarding any mutations
When to use WGS/WES - ANS WGS is more informative, locates all mutations
WES: cheaper and quicker
Genetic modifier that is impacting a disease - ANS EX: Different MBL expression affects
mucus production and microbe destruction in lungs
Single gene disorder - ANS Disorders leaning towards genetic causes (eg. single gene
epilepsy)
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
EXAM QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
Define case - ANS Affected individuals
Define controls - ANS Non-affected individuals
Case control studies - ANS Pair affected individuals with non-affected, matched according to
environment exposure, occupation, geographical location. Ideally only difference should be
disease presence. Compare extended families of both affected/non affected
Odds ratio - ANS Odds individual with a specific variant develops disease
Odds ratio calculation - ANS Ratio between
= odds of being affected with variant present : odds of being affected with NO variant present
Odds of being affected with variant present calculation - ANS Number of cases with variant /
Number of controls with variant
High odds ratio indicates.. - ANS very likely that the variant's presence indicates disease
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Sources of bias in twin studies - ANS Shared environment for siblings
Ascertainment bias
Recall bias
Odds of being affected with NO variant present calculation - ANS Number of cases without
variant / Number of controls without variant
Shared environment for siblings - ANS May lead to overestimate of heritability of trait
Ascertainment bias - ANS Families with more than one affected sibling are more likely to
come under attention of researcher
Recall bias - ANS Unrealistic to examine all relatives directly, may have to rely on anecdotal
memories
Purpose and utility of whole genome sequencing - ANS WGS provides full information
regarding any mutations
When to use WGS/WES - ANS WGS is more informative, locates all mutations
WES: cheaper and quicker
Genetic modifier that is impacting a disease - ANS EX: Different MBL expression affects
mucus production and microbe destruction in lungs
Single gene disorder - ANS Disorders leaning towards genetic causes (eg. single gene
epilepsy)
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
