Difference Between Somatic and Germline Gene Therapy

Table of Contents

The key difference between Somatic and Germline Gene Therapy depends on the type of cells used to do the gene therapy. Somatic Gene therapy refers to the introduction or alteration of genes in somatic cells. Germline Gene therapy refers to the introduction or alteration of genes in germ cells.

Gene therapy is currently an upcoming field of treatment as it targets the cause of the disease. By altering the genes responsible for a particular disease condition, it is possible to eliminate the disease at an early stage. Therefore, the gene therapy has shown novel methods in disease cure and disease elimination.

CONTENTS

1. Overview and Key Difference
2. What is Somatic Gene Therapy
3. What is Germline Gene Therapy
4. Similarities Between Somatic and Germline Gene Therapy
5. Side by Side Comparison – Somatic vs Germline Gene Therapy in Tabular Form
6. Summary

What is Somatic Gene Therapy?

Somatic Gene therapy refers to a type of gene therapy where the genes present in somatic cells are altered to cure the disease. The gene profiles are analysed to find mutated or defective genes. Hence, this therapy uses the Antisense technology, which silences the defective gene or introduces the healthy gene via transformation techniques.

There are two types of somatic gene therapy; ex vivo and in vivo.  Ex vivo somatic gene therapy involves the extraction of cells out of the system, whereas in vivo somatic gene therapy occurs when the cells are within the system.

Difference Between Somatic and Germline Gene Therapy

Figure 01: Somatic Gene Therapy

Somatic cells are non-reproductive. Therefore, there are less ethical concerns in this approach. Somatic gene therapy is applicable for cystic fibrosis, muscular dystrophy, and some infectious diseases.

What is Germline Gene Therapy?

Germline Gene Therapy is a more specific form of gene therapy where the genes present in germ cells as it can alter the sperm cells of males and egg cells of females. Germline therapy performs at fetal stage using karyotyping to identify defective genes present in the fetus. Upon identification of defective genes, removing them, altering them and introducing new genes are possible.

Because this therapy alters the germ cells, finally their alterations move on to the next generation and thus is reproducible. Therefore, it is necessary to evaluate a lot of ethical considerations before the germline gene therapy. Germline gene therapy is useful for genetic disorders such as ADA deficiency, PNP deficiency and Lesch – Nyan Syndrome, etc.

What are the Similarities Between Somatic and Germline Gene Therapy?

  • Both Somatic and Germline Gene therapies involve altering of defective genes or introducing of healthy genes.
  • Both therapies use gene transformation methods.

What is the Difference Between Somatic and Germline Gene Therapy?

Somatic vs Germline Gene Therapy

Somatic Gene therapy refers to the alteration of the genome of somatic cells by transferring therapeutic genes.Germline Gene therapy refers to the alterations of the genome of the germ cell by introducing therapeutic genes.
 Type of Cells Involved
Somatic gene therapy uses Somatic cells.Germline gene therapy uses Germ cells such as sperm cells and egg cells.
Reproducibility
Alterations done by somatic gene therapy are non-reproducible. Hence, do not pass to the next generation.Alterations done by germline gene therapy are reproducible. Hence, pass into the next generation.
 Transformation Technical Approaches
Techniques used in somatic gene therapy are relatively simple. Hence, can be performed under in vitro conditions.Techniques are very complex since it involves fetal samples.
Ethical Issues Involved
Less or no ethical issues exist regarding somatic gene therapy.High ethical considerations are existing for germline gene therapy.
Conservativeness
Somatic gene therapy is more conservative.Germline gene therapy is less conservative.

Summary – Somatic vs Germline Gene Therapy

Gene therapy involves alteration of genes, removal of defective genes, or introduction of healthy genes as a method of treatment for genetic disorders and diseases. Somatic Gene Therapy is the Gene therapy performed on somatic cells that are nonreproductive while Germline gene therapy is the gene therapy done on germ cells that are reproductive. This is the difference between Somatic gene therapy and germline gene therapy.

Reference:

1.“Germline Gene Therapy – Should Genetic Manipulation of Human Genes That Affect Future Offspring Be Allowed? .” Germline Therapy. Available here
2.Administrator. “Types of Gene Therapy.” Overview of Gene Therapy Methods and Types of Gene Therapy. Available here

Image Courtesy:

1.’In vivo gene therapy’By Lizanne Koch – own work  (Public Domain) via Commons Wikimedia

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