Promising results shown in the treatment of g
Researchers at NUS Yong Loo Lin School of Medicine (NUS Medicine) have shown that gene therapy using a single dose injection of a virus carrying the ‘right’ gene can potentially be used to cure hormone resistant dwarfism of growth, also known as ‘Laron’s Syndrome’.
People with Laron syndrome are very small because their bodies are unable to use growth hormone, a substance that helps the body grow. The team led by Professor Lee KO, from the Department of Medicine at NUS Medicine, attempted to increase a hormone called insulin-like growth factor 1 (IGF1) in a laboratory model by replacing the faulty receptor gene of growth hormone, using a virus containing instructions. specifically targeted at the liver. The liver is the main organ producing the IGF1 hormone. Previously, the only treatment available was the injection of genetically engineered recombinant insulin-like growth factor 1 (rhIGF1), given daily or even twice daily. However, the results of this original treatment have not been ideal.
The team previously generated a specific gene delivery tool, called AAV8 transporter, which expressed the human insulin gene in the liver. When this showed the potential to be used by diabetic patients as a long-term basal gene therapy for insulin, the team of researchers which included Dr. Sia Kian Chuan and Dr. Gan Shu Uin from the Department of Surgery, attempted to further explore the potential of the AAV8 gene delivery tool to understand the extent of its effectiveness. The results showed significant height and weight that increased steadily throughout 26 weeks, compared to the untreated lab model.
Other researchers have shown that there is persistent gene expression for up to 10 years to produce proteins in the liver necessary for growth, following the administration of a single dose of AAV. This makes AAV gene therapy an attractive treatment with potentially very good therapeutic results.
Using an AAV8 gene delivery tool, gene therapy has become a safe and effective treatment with the potential to treat a variety of inherited or rare mutation disorders such as hemophilia and spinal muscular atrophy. There were no treatments available for these disorders before. With these optimistic results, the AAV vector can potentially be used to treat people with Laron syndrome.
Professor Lee said: ‘Gene therapy has given us a promising start in the management of dwarfism. This is much more favorable compared to injections of rhIGF1, once or twice a day for many years, which causes side effects of pain and discomfort in patients and represents a huge financial burden for those involved.