Another inherited liver disorder is the glycogen storage disease type 1a (GSD-1a) or von Gierke disease, which occurs in about 1 out of 100,000 births. A normally-functioning liver takes glucose from the blood stream and stores it as glycogen. This glycogen is then used as an energy source by the body. In GSD-1a, the enzyme microsomal glucose-6 phosphate (G6Phase) that assists the liver in storing the glycogen, is not produced. So the liver has a problem with storing and releasing glycogen. Due to this the sugar levels in the blood drop. If the blood sugar level drops too much, the patient can suffer seizures and organ damage.
Following a special diet can help with maintaining the glucose levels, but in the long run this does not prevent liver damage or rule out the possibility of cancer or kidney failure.
Researchers at Duke University Medical Center have devised a gene therapy technique where the correct genetic code, by way of a harmless virus vector, is inserted into the liver cells to induce them to produce the necessary enzyme.
In experiments conducted on mice and dogs, gene therapy replaced the missing enzyme in the liver to fully normal levels and the patients were protected from low glucose for up to a year.
The problem with gene therapy is that when the liver cells divide and reproduce, the enzyme genes are not transferred with them. They will need to be introduced anew. However, as liver cells divide very slowly, researchers feel that a few shots may suffice over a long period of time.