Germ-line gene therapy is ?

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Pathology & Genetics

Easy

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

Germ-line gene therapy specifically targets reproductive cells, which are also known as germ cells (sperm and eggs).
The primary goal is to introduce functional genes into these cells to correct a genetic defect.
Because the genetic modification is within the reproductive cells, the change is passed on to the organism's offspring.
This makes the genetic alteration heritable, meaning it will be present in every cell of the offspring and can be passed down through subsequent generations.

Option A: This describes somatic gene therapy, not germ-line therapy. Somatic therapy targets non-reproductive cells, and the genetic changes are confined to the individual patient and are not passed to their children.
Option B: The changes made in germ-line therapy are fundamentally heritable. The modification is integrated into the genome of the reproductive cells, ensuring it is passed on to all offspring, not just 'sometimes'.
Option C: The entire concept and purpose of germ-line gene therapy are centered on heritability. Its goal is to alter the genetic legacy of a family to remove a hereditary disease, which is a direct manipulation of heritability.

Visual 1: Diagram - A flowchart comparing Germ-line and Somatic gene therapy. It should show a person receiving therapy, with an arrow from germ-line therapy pointing to their offspring (labeled 'Heritable') and an arrow from somatic therapy stopping at the individual (labeled 'Not Heritable').

Clinical Relevance

Nursing practice connection: Knowing Heritability of Germ-line Gene Therapy helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
While germ-line gene therapy holds the theoretical promise of eradicating genetic diseases like Huntington's or cystic fibrosis from a family line forever, it is not performed in humans due to profound ethical concerns.
These concerns include the potential for unforeseen long-term effects on the human gene pool and the moral questions surrounding the modification of human heredity.
What if? If gene therapy targeted a patient's liver cells to treat a metabolic disorder, it would be somatic gene therapy. The patient's condition might improve, but they could still pass the genetic defect to their children because their reproductive cells are unaffected.

How to Approach the Question

First, identify the key term in the question: 'Germ-line gene therapy'.
Recall the definition of 'germ-line'. The word 'germ' refers to germ cells, which are the body's reproductive cells (sperm and egg).
Connect this to the concept of inheritance. Changes made to reproductive cells are passed on to offspring.
Evaluate the options based on this understanding. 'Heritable' directly means 'can be inherited'.
Eliminate the other options: 'Not heritable' applies to somatic therapy, and the other two options misrepresent the fundamental principle of the therapy.

Concept Tested & Keywords

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