Researchers at the Indian Institute of Technology (IIT) Madras, Tel Aviv University, and Columbia University are investigating a rare genetic brain disease called "GNB1 Encephalopathy" and attempting to develop a drug to effectively treat it. GNB1 Encephalopathy is a neurological disorder that affects individuals in the fatal stage, with fewer than 100 documented cases worldwide. Symptoms include delayed physical and mental development, intellectual disabilities, and frequent epileptic seizures.
According to Haritha Reddy, a former PhD scholar at IIT Madras, the disease is caused by a single nucleotide mutation in the GNB1 gene that leads to the creation of the "G'1 protein," which is one of the G-proteins. "This mutation affects the patient since they are a foetus. Children born with GNB1 mutation experience mental and physical developmental delay, epilepsy (abnormal brain activity), movement problems. To date, less than a hundred cases have been documented worldwide. However, the actual number of affected children is probably much greater as diagnosis is not widely available since it requires a sophisticated and expensive procedure," Reddy explained.
G-proteins and GPCR Signalling
Every cell in the human body contains a variety of signalling molecules and pathways that help in communicating with other cells and within itself. The main signalling mechanism used by cells is "G-Protein Coupled Receptor" (GPCR) signalling. GPCR is a receptor that receives a signal (e.g., a hormone, light, neuro transmitter) from the outside of the cell and transduces it to the inside of the cell.
GPCR is present in the cell membrane and has a G-protein (a'?) attached to it from inside the cell. G-proteins are the downstream molecules that relay the signal received by the GPCR. These G-proteins are present in every cell, and any malfunction will cause disease. Mutations in the GNB1 gene lead to the neurological disorder GNB1 Encephalopathy, characterized by general developmental delay, epileptic form activity in the electroencephalogram (EEG), seizures of several types, muscle hypertonia or hypertonia, and additional variable symptoms.
Developing a Treatment for GNB1 Encephalopathy
Amal Kanti Bera, Professor of the Department of Biotechnology at IIT Madras, noted that as GNB1 encephalopathy is a rare and less-known disease, not much research has been done on it. "We don't know the mechanisms that underlie the disease. We don't know how to treat this disease. Therefore, it is important to do research on GNB1 encephalopathy. We have a long way to go. It is not easy to develop a drug for treating this disease effectively," Bera said.
The researchers are currently working on developing preclinical animal models of the disease, with the hope of developing personalized disease models within three years that will be useful in research and drug screening.
Gene Therapy as a Treatment Option
Nathan Dascal, Professor at Tel Aviv University, explained that as the developmental issues associated with GNB1 Encephalopathy begin at the fatal stage, gene therapy is the most plausible option for alleviating the effects of the mutation. However, the development of this complicated procedure will take many years and significant investment.
On the other hand, epilepsy, which is a common symptom of GNB1 Encephalopathy, can be treated using specific drugs to improve the patient's quality of life.