Patterns of Inheritance
Anatomy · Topic 74
Source: NMC CBME Curriculum 2024 · Volume I · Anatomy · Topic 74 · combined PDF page 145
Practice questions
- A condition consistently appears in successive generations, and affected individuals of either sex can have affected children. Which inheritance pattern best fits this pedigree?
- A heterozygous person with a fully penetrant autosomal dominant condition has children with a partner who does not carry the variant. What is the probability that each child inherits the variant?
- Two clinically unaffected parents have an affected child, and the condition is known to be autosomal recessive. Which parental genotypes best explain this observation?
- For two heterozygous carriers of the same autosomal recessive variant, what is the probability that a child will be affected in each pregnancy?
- A pedigree shows affected males connected through clinically unaffected women, with no father-to-son transmission. Which pattern is most consistent with these observations?
- An affected father with a classic X-linked recessive condition has children with a mother who is confirmed not to carry the variant. Which outcome is expected under this model?
- Under a classic X-linked dominant model, an affected father and an unaffected mother have children. Which transmission pattern is expected?
- A clearly affected father has an affected son. Which inference is most appropriate when considering a classic X-linked inheritance model?
- A woman with a mitochondrial DNA variant has children with an unaffected man. Which statement best describes the usual inheritance expectation?
- Which statement is supported by the supplied review of mitochondrial disease inheritance?
- A variant's phenotypic effect depends on whether it was inherited from the mother or the father. Which genetic mechanism best explains this?
- Two individuals carry the same genetic alteration, but its clinical effect differs according to whether it was inherited maternally or paternally. Which feature is most directly implicated?
- Which disorder is specifically cited in the supplied review as having evidence for an imprinting contribution to atypical inheritance?
- In a proposed digenic model, variants at two different genes are both required to explain a phenotype. What is the defining feature of this model?
- Which description best matches the term “triallelic inheritance” as used in discussions of atypical inheritance?
- A patient has a monogenic disorder, but clinical severity differs among individuals with similar findings at the primary disease locus. Which mechanism can help explain this variability?
- The supplied atypical-inheritance review discusses modifier-gene effects in which of the following disorders?
- A disease-associated primary genotype does not fully account for variation in clinical phenotype. Which explanation is consistent with the supplied review's discussion of cystic fibrosis?
- A common disease is described as arising from multiple genetic factors together with environmental influences, without a classic single-gene pedigree. Which inheritance category best fits?
- A disorder is characterized in the supplied systematic review as multifactorial in most cases, with classic inheritance patterns generally not demonstrable. Which disorder is being described?
- A newborn has a congenital heart defect. Which broad inheritance description best reflects the supplied 2024 study's characterization of congenital heart defects?
- A family history of a common disorder is positive, but affected relatives do not fit a consistent single-gene segregation pattern. Which interpretation is most appropriate?
- A clinician evaluating chronic kidney disease considers both classical monogenic patterns and complex disease influenced by environmental factors. Which statement best reflects the KDIGO conference report?
- According to the KDIGO conference report, which approach is specifically part of “thinking genetic” in a patient with chronic kidney disease?
- A genome-wide association study reports a congenital heart defect risk locus with an odds ratio of 1.15. Which interpretation is most appropriate in the context of the study's description of congenital heart defects?
- A clinician is comparing a clearly segregating single-gene kidney disorder with a kidney disorder that arises through multiple genetic and environmental contributions. Which distinction is most accurate?
- A patient with a suspected hereditary disorder has a phenotype that is not fully predicted by the identified primary genotype. Which conclusion is most consistent with the supplied review of atypical inheritance?
- A trait is associated with several genetic risk loci, yet most individuals with the trait do not have a clear family pattern consistent with one gene. What is the best interpretation?