Understanding Cell and Gene Medicine

As patient advocates, your message continuity is important. Cell and gene medicine incorporates a complex lexicon that can be confusing.  Within our communities, including patients, caregivers, health care providers, medical researchers and scientists, policy makers, the public and the media, there is a wide gap in knowledge and awareness about cell and gene medicine.

The ARM Foundation slide show, Understanding Cell & Gene Medicine, can be used to help different stakeholders understand the fundamentals of cell and gene medicine, including gene therapy, gene editing, cellular therapy, and regenerative medicine.

Talking to the General Public about Cell and Gene Medicine

Sometimes, a disease or debilitating health condition is caused by one or more genetic changes in the body. Many diseases or conditions caused by defective genetic code have few treatment options. Conventional medicine often treats the unwanted symptoms of the disease or slows down the disease. Doctors use cell and gene medicine to try to resolve the underlying genetic defect that is causing an incurable disease or health condition.

Cell and gene medicine are part of Regenerative Medicine, which draws on insights of late 20th century cell biology, molecular biology, chemistry, computer science, bioengineering, genetics, medicine, robotics, and other fields to understand and harness the body’s repair and development mechanisms. Regenerative medicine addresses many of the most challenging health issues in medicine. Treating the genes themselves, that are the root causes of gene-based diseases and disorders, is the aim of Gene Medicine. In Cell Therapy, cells themselves are used as agents of repair or restoration of function.

Understanding Genes and Defective Genes

Genes are regions of DNA that direct the production of proteins and direct biologically important functions throughout the body. Genes are inherited from our biological parents.

  • DNA is the name of a molecule.
  • Each DNA molecule is made up of a sequence of building blocks called nucleotides and there are only 4, known by the letters A G C and T.
  • On the rungs of the famous double helix, the DNA molecules are paired, A with T and G with C
  • A gene is a specific sequence of DNA molecules that act as the instructions for making protein. The Specific sequence of the DNA is called the Genetic Sequence .
  • The genetic sequence is written out as letters like TGCATTG, or GATTACA.

People have around 25,000 genes. We typically get two copies of each gene, one from each of our parents. These genes influence everything from the color of our hair to the power of our immune system, but genes aren’t always assembled correctly. Mutations, or errors, in genes can cause disease by failing to produce sufficient levels of a functional protein. A mutation is a change in the genetic sequence. Not all mutations have bad effects.

Genes can operate incorrectly when:

  • inherited mutations pass from parents to babies
  • when 2 recessive disease causing genes are received from 2 parents
  • when one dominant disease-causing gene is received from one parent in eggs or sperm
  • a gene mutation occurs as the cells are replicating
  • a gene mutation occurs as the chromosomes are dividing in half during the creation of eggs or sperm
  • age causes mutations (changes) over time
  • the genes are damaged by chemicals and radiation, or other environmental toxins. For example, Skin cancer is one disease caused by long-term changes to cells after too much exposure to sunlight’s ultraviolet radiation.
  • Other gene mutations can occur when a piece of genetic code is missing, defective, or duplicated in error during pregnancy. Larger mutations can affect many genes on one chromosome. Defective genes can result in a disease or medical disorder.

Introduction to Cell and Gene Medicine

Today, technologies show promise for combatting gene-based diseases and resolving other conditions that may be reduced or reversed by cell and gene medicine. Single-gene disorders are at present thought to be more amenable to gene therapy than chromosomal or complex disorders.

SINGLE-GENE DISORDERS

 THERAPEUTIC APPROACH

Cystic Fibrosis

 Gene therapies are in development

Sickle Cell Disease

 Gene Editing approaches are in Clinical Trials

Spinal Muscular Atrophy

 Zolgensma & Spinraza are approved gene therapy products

Huntington Disease

 A gene therapy is in clinical trial

Fragile X Syndrome

Gene therapy approaches are in development

FAQ: What is the difference between traditional prescription drug therapy and gene and cell therapy?

Prescription pharmaceutical medications are typically used to manage diseases, mitigate symptoms and relieve pain. The concept behind gene and cell therapy is to target the genetic cause of the disease.  The goal is to rid the person of recurring symptoms, ideally after a single treatment. Gene therapy adds working genes within specific cells.

Currently, the therapies cannot be delivered as a standard type of drug available at a pharmacy. Instead, you find approved gene therapies at designated treatment centers. Gene therapies aim to treat diseases that currently have no treatments, where treatment options do not work well, or are high risk without the possibility of a cure. Gene therapy offers promise to treat rare inherited disorders. Of the 7,000 rare diseases that exist, 95 percent have no approved current treatment.

It is worth noting that gene therapy targets somatic cells, the vast majority of cells in the body.  Gene Therapy does not target our reproductive or “germline” cells, our sperm or our eggs. This means that the treatment is corrective to the patient only and is not passed to the next generation. 

Many diseases and health conditions may be improved by cell and gene medicine.  A list of Approved Therapies is found here.