The Future of Medicine: Recent Breakthroughs in Gene Therapy

Advances in gene therapy for treating genetic diseases

What are genetic disorders?

Genetic diseases are disorders that happen because of changes or mistakes in a person's genes. These changes can be passed down from parents or happen on their own. Genetic diseases can affect any part of the body and can cause different symptoms depending on the disease. Some examples of genetic diseases include cystic fibrosis, sickle cell anaemia, and Down syndrome. While there is no cure for most genetic diseases, some treatments are available to help manage symptoms and improve the person's quality of life.

Many examples of genetic diseases can affect any part of the body, including the brain, heart, liver, kidneys, and immune system. Here are some common examples:

1. Cystic fibrosis
2. Sickle cell anaemia
3. Huntington's disease
4. Hemophilia
5. Down syndrome
6. Muscular dystrophy
7. Tay-Sachs disease
8. Phenylketonuria (PKU)
9. Marfan syndrome
10. Achondroplasia (a type of dwarfism)
11. Fragile X syndrome
12. Turner syndrome
13. Klinefelter syndrome
14. Prader-Willi syndrome
15. Angelman syndrome

It's worth noting that this is not an exhaustive list, and many other genetic diseases exist.

Genetic Disorders

Advances in gene therapy for treating genetic diseases

Gene therapy is a rapidly advancing field with great promise for treating genetic disorders. It involves introducing genetic material into a patient's cells to correct or replace a defective gene or to add a new gene that will enable the body to produce a missing protein. Recent advances in gene therapy have led to some remarkable successes in treating genetic diseases. 

Some complicated genetic diseases,

• Spinal muscular atrophy (SMA): SMA is a genetic disease that causes muscle weakness and wasting and can be fatal in its most severe form. In 2019, the FDA approved a gene therapy called Zolgensma for SMA in children under two. Zolgensma is a one-time treatment that replaces the defective SMN1 gene with a functional copy of the gene, leading to improved muscle strength and function.
• Hemophilia: Hemophilia is a genetic disorder that affects the body's ability to clot blood. In 2020, the FDA approved a gene therapy called Hemlibra for haemophilia A in patients resistant to other treatments. Hemlibra works by replacing a missing clotting factor and improving blood clotting.
• Leber congenital amaurosis (LCA): LCA is a rare genetic disease that causes severe vision loss and blindness in infants and children. In 2017, the FDA approved a gene therapy called Luxturna for LCA caused by mutations in the RPE65 gene. Luxturna is a one-time treatment that introduces a functional copy of the RPE65 gene into the patient's retinal cells, leading to improved vision.
• Sickle cell disease: Sickle cell disease is a genetic disorder that causes red blood cells to become misshapen and break down, leading to anaemia and other complications. In 2021, the FDA approved a gene therapy called Oxbryta for sickle cell disease in patients 12 years and older. Oxbryta works by increasing the production of fetal haemoglobin, which can help prevent misshapen red blood cells from forming.

These advances in gene therapy represent a step forward in genetic diseases. While overcoming many challenges, including improving the safety and efficacy of gene therapies, the potential benefits for patients with genetic disorders are immense.

What has recently changed regarding spinal muscular atrophy (SMA)?

Spinal muscular atrophy (SMA) is a rare genetic disorder that affects the nervous system and causes muscle weakness and atrophy. Recent advances in the treatment of SMA have focused on the progress of drugs that target the underlying genetic cause of the disease.

The US Food and Drug Administration (FDA) approved a drug called nusinersen (marketed as Spinraza) in 2016, which is a breakthrough in the treatment of Spinal Muscular Atrophy (SMA). Nusinersen works by increasing the production of a protein called SMN, which is essential for the survival of motor neurons. By increasing SMN levels, nusinersen helps to improve muscle function in individuals with SMA.

Another recent advance in the treatment of SMA is the development of gene therapy. In gene therapy for SMA, scientists deliver a working version of the SMN1 gene (typically faulty in people with SMA) to motor neurons using a viral vector. This approach has shown promising results in clinical trials, and several gene therapies for SMA are currently in development.

In addition to these therapies, there are also ongoing efforts to improve the management of SMA through multidisciplinary care and the use of assistive devices such as braces, wheelchairs, and respiratory support. These recent advancements offer hope for improved outcomes and quality of life for individuals with SMA.

 What is the modern treatment for Leber congenital amaurosis (LCA)?

One recent advancement in the treatment of Leber congenital amaurosis (LCA) is the development of gene therapy. In 2017, the US Food and Drug Administration (FDA) approved the first gene therapy for inherited retinal diseases, including LCA. This therapy, called Luxturna, uses a viral vector to deliver a functional copy of the RPE65 gene to retinal cells. RPE65 is a gene mutated in some forms of LCA, leading to vision loss. By providing a copy of the gene, Luxturna can restore some vision in individuals with LCA. This gene therapy has shown promising results in clinical trials and has the potential to improve the quality of life for individuals with LCA.

What are the latest developments in the treatment of sickle cell disease?

There are recent advancements in the treatment of sickle cell disease. One breakthrough is the development of gene therapy as a potential cure. In 2019, the US Food and Drug Administration (FDA) approved the first gene therapy for sickle cell disease, called Zolgensma. This therapy uses a viral vector to deliver a functional copy of the HBB gene (mutated in individuals with sickle cell disease) to bone marrow cells, which can then produce healthy red blood cells.

Another recent advancement in sickle cell disease is the development of new drugs, such as voxelotor and crizanlizumab. Voxelotor is a drug that helps to prevent sickle-shaped red blood cells from forming, as crizanlizumab is an antibody therapy that helps to reduce the frequency of vaso-occlusive crises (painful episodes caused by blocked blood vessels).

Additionally, there has been progressed in the use of bone marrow transplants as a treatment for sickle cell disease. Researchers have been exploring new ways to make bone marrow transplants safer and more effective for individuals with sickle cell disease, including using less toxic conditioning regimens and developing techniques to match donors more accurately.