Scientists are well aware that genes play a role in whether a person is affected with Alzheimer’s. More light was shed on the topic when a study was published today in the journal Neurology that said there was a possible increased risk in developing the disease when both parents have late-onset Alzheimer’s.
The study tested cognitively normal adults who had two parents that had late-onset Alzheimer’s and found that they may exhibit signs of the disease in brain scans years or even decades earlier than they show symptoms. New York University School of Medicine’s Lisa Mosconi, PhD, said that this is critical because when most people come in for a diagnosis there can already be “a large amount of irreversible brain damage” and finding indications of the disease in those considered high-risk is ideal.
The study tested 52 people, ages 32 to 72, with normal brain function. The test subjects were broken into four equal groups of different backgrounds: those with a father with Alzheimer’s, a mother, both parents and those with no genetic history. The subjects were then given multiple brain scans including Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) scans.
The scans showed that there was a possible increase in Alzheimer’s risk when both parents have the disease. The abnormalities in the brain were the most distinct in those with both parents affected by late-onset Alzheimer’s. Also, the abnormalities were more distinct in those with a mother affected by the disease than those with a father who was affected. All three groups with a hereditary disposition showed a greater loss of gray matter and more plaque in the brain than those who had no family history of Alzheimer’s.
Although there may be early changes in the brain for those with a hereditary disposition, the study does not definitively predict whether someone will get Alzheimer’s because all the subjects exhibited healthy cognitive function.
The research is not currently of use for helping people avoid Alzheimer’s or even identifying whether or not they will get the disease. The hope is that, in the future, this research could be the beginning of the possibility of helping those at risk by identifying the earliest signs. In turn, it may help doctors pinpoint the patients that could be helped by therapy aimed at delaying, or even possibly preventing, Alzheimer’s progression.
Neurologist Dr. Ronald Kanner of Manhasset, New York’s North Shore University Hospital, who was not involved in the study, said that now they need to do a follow-up over the long-term. He added that this would help to see whether the brain indicators “do give early warning” for at-risk people. Regardless, Kanner said the research is “quite significant” because it gives more evidence to the genetic factors involved with Alzheimer’s.
Although there is a possible increase in Alzheimer’s risk when both parents have the disease, there are plenty of people with “Alzheimer’s brain pathology” who do not go on to have the disease, according to Mosconi. Mosconi said that for now the best way to prevent Alzheimer’s that is within control is to maintain a healthy lifestyle.
By Rebecca Hofland