Examkin

Question

Difficulty: EasyGenetic and Molecular Mechanisms

Match each classic genetic principle to its defining clinical or pathophysiological description.

  • A genetic disorder presents at an earlier age of onset and with more severe symptoms in successive generations of a family.Anticipation
  • A single gene mutation causes multiple diverse phenotypic traits across different organ systems, such as simultaneous ocular, cardiovascular, and skeletal abnormalities.Pleiotropy
  • The clinical expression of a disease differs significantly based on whether the responsible mutant allele was inherited from the maternal or paternal parent.Genomic imprinting
  • Pathogenic mutations in entirely different genes located on different chromosomes result in the exact same clinical disease presentation.Locus heterogeneity

Answer

Anticipation matches with increasing disease severity in successive generations. Pleiotropy matches with a single mutation causing diverse multi-organ traits. Genomic imprinting matches with parent-of-origin dependent disease expression. Locus heterogeneity matches with distinct gene mutations yielding identical clinical presentations.
Each definition precisely describes a foundational genetic mechanism essential for interpreting clinical genetic presentations and pedigree charts in practice. Proper alignment matches anticipation with generational severity, pleiotropy with multi-organ effects, imprinting with parent-of-origin expression, and locus heterogeneity with distinct loci causing identical phenotypes.

Step-by-Step Solution

1
Analyze the description regarding earlier onset and increased severity in successive generations.
Identified as Anticipation.
This is the textbook definition of anticipation, heavily linked to dynamic mutations like trinucleotide repeat expansions.
2
Analyze the description of diverse traits across organ systems caused by one mutation.
Identified as Pleiotropy.
Pleiotropy occurs when one underlying molecular defect has widespread, seemingly disconnected manifestations.
3
Analyze the description of parent-of-origin effects on disease expression.
Identified as Genomic imprinting.
Epigenetic methylation specific to maternal or paternal gametes drives imprinted gene expression.
4
Analyze the description of different chromosomal mutations causing the same exact disease.
Identified as Locus heterogeneity.
Different loci leading to the same phenotype defines locus heterogeneity, differentiating it from allelic heterogeneity (different mutations in the same gene).

Key Concept

Foundational genetic inheritance principles and variations
Rate this question

Topics

Genetic and Molecular Mechanisms

More questions from this topic