NURS 6501: Final Exam: Please contact Assignment Samurai for help with NURS 6501: Final Exam or any other assignment. Email: assignmentsamurai@gmail.com   Family studies have shown that OCD has a significant genetic component. Which of the following best describes the inheritance pattern most commonly associated with OCD? Group of answer choices

• Autosomal dominant with complete penetrance
• X-linked recessive
• Polygenic with variable expressivity
• Mitochondrial inheritance

  The correct answer is: Polygenic with variable expressivity   Explanation: Obsessive-compulsive disorder (OCD) does not follow a simple Mendelian inheritance pattern (e.g., autosomal dominant, autosomal recessive, or X-linked). Instead, research suggests that OCD is:

• Polygenic: Multiple genes contribute to the risk of developing OCD.
• Variable expressivity: Even among individuals with genetic susceptibility, symptoms can vary widely in severity and presentation.
• Influenced by environmental factors: Stress, trauma, and infections may interact with genetic predisposition.

Family and twin studies support a heritable component, but no single gene or simple inheritance pattern explains OCD. Thus, polygenic inheritance with variable expressivity best describes its genetic basis. The other options are incorrect because:

• Autosomal dominant with complete penetrance would mean a single gene mutation always causes OCD, which is not the case.
• X-linked recessive would show a specific gender-linked pattern, which is not observed in OCD.
• Mitochondrial inheritance would involve maternal transmission only, which is not a recognized pattern for OCD.