Feb. 14 (UPI) -- Researchers from The Flanders Institute for Biotechnology, or VIB, in Belgium have discovered that children of parents with the C9orf72 genetic mutation are at an increased risk of developing frontotemporal dementia, or FTD, and amyotrophic lateral sclerosis, or ALS.
FTD and ALS are two brain diseases that cause neurodegeneration of brain cells. The frontal lobes and temporal lobes are affected first in FTD causing behavior and personality changes in patients with memory loss occurring later. ALS affects the nerve cells that control muscles in the brain and spinal cord causing patients to progressively lose muscle mass and strength leading to loss of speaking, swallowing and eventually breathing. A mutation of the C9orf72 gene is the most common cause of FTD and ALS.
Researchers from VIB and the University of Antwerp have found that if a parent passes the mutation on to their children, the children can begin to be affected with the disease at a younger age than their parent.
"In a new clinical study in 36 C9orf72 families, we analyzed the age of onset of the patients in 2 to 4 generations," Dr. Sara Van Mossevelde of VIB-UAntwerp, co-author of the study, said in a press release. "We found that there was a significant difference in the ages of onset between successive generations. In most families, the children were affected by the disease at a younger age, but there were no indications that the disease was progressing more quickly. We also found that in families with both FTD and ALS patients, if the parent had FTD the child was more likely to have FTD, and a similar principle applied to ALS."
The new study was published in JAMA Neurology.
"This research is based on our team's previous results, which showed that the same C9orf72 mutation leads to both FTD and ALS," Professor Christine Van Broeckhoven of VIB -UAntwerp and co-author of the study, said in a press release. "As this mutation occurs in a substantial group of ALS and FTD patients, it is important to extract as much knowledge about this mutation and the disease process as possible."
Previous research by Van Broeckhoven and her team found a a mutation in the C9orf72 gene in both FTD and ALS patients.
"The C9orf72 mutation is the most frequent mutation in FTD and ALS," Van Broeckhoven said. "In the Belgian population, 37 percent of patients with ALS and 25 percent of patients with FTD can be explained by the presence of this C9orf72 mutation. The C9ord72 mutation is present in 88 percent of patients with FTD plus ALS."
The mutation in C9orf72 is made up of a repetition of a short DNA sequence GGGGCC and the age of onset of FTD and ALS is determined by the number of GGGGCC repeats with the more repetition, the earlier the age of onset.