Deficient growth factor responsible for variant dementia
Some people with frontotemporal dementia (FTD) have lower levels of the growth factor progranulin. This circumstance most likely leads to the death of cells in the frontal lobe of the brain. The function of progranulin in the brain is still unclear.
FTD patients occasionally have a mutated progranulin gene, observed Christine Van Broeckhoven's international research team. In a genetic analysis of 42 patients, the scientists identified a total of nine different progranulin mutations. Broeckhoven, a researcher at the University of Antwerp, emphasizes that the defective progranulin would produce less growth factor. Apparently, only the protein deficiency caused cell death in the frontal lobe of the brain in the patients studied. Until now, scientists have believed that accumulated defective proteins - most notably the tau protein in FTD - are responsible for the development of neurodegenerative diseases such as Alzheimer's and Parkinson's.
FTD might be combated in some patients if doctors administer this progranulin, the researchers hope. However, this is not easy, because if the amount of the growth factor is too high, tumors will form again.
The progranulin gene is located on chromosome 17 near the tau gene. Researchers believe that defective genes in this chromosome are responsible for the symptoms of the disease. FTD is the second most common form of dementia, after Alzheimer's disease, which also affects people under the age of 65. FTD sufferers have damaged cells in the frontal brain lobe, which controls cognitive processes such as memory and language, among other things.