Which parent is more likely to pass down Alzheimer’s disease? New research has the answer

Alzheimer's can be passed down from parents to children, but new research reveals whether a particular parent is more likely to be responsible.  

Research can give us more information about our bodies and genetic makeup than ever before - if you've ever wondered about the traits passed on by your parents, you can now find out which one is responsible for everything from your intelligence to your fertility levels. Even more incredible, is the fact you can inherit your grandparents' trauma even if you never met them.  

Recently, there's been a lot of time and coverage given to whether Alzheimer's could be predicted. It's been found that the less common form of the disease, Familial Alzheimer's Disease (FAD) is inherited, although it's a good idea to point out there are ways of lowering the risk even if it does run in your family. However, new research looks at whether your mum or dad is more likely to pass on the condition. 

The study looked at 4,000 cognitively normal adults aged between 65 - 85, living in the US, Canada, Japan, and Australia. Candidates were asked if either parent ever developed Alzheimer’s or dementia, and the age of onset. The findings reveal that the risk of the conditions being passed down to children was higher when mum, rather than dad, was affected. 

To break down why this might be the case, scientist Dr. William A. Haseltine has some theories. Writing for Forbes, he points out that mothers will always pass down an X chromosome. He suggests there could be sex-specific differences in this chromosome that increase the risk of Alzheimer’s disease - it could be more vulnerable to epigenetic changes giving them the ability to turn specific genes on and off.

When daughters have two X chromosomes, genes in the X chromosome passed down by dad could be silenced or inactivated. Because of this, mutations in X chromosomes passed down by dad, could have little or no impact on the child. However, it's believed further research is required to prove this as a theory.

Dr. Haseltine further suggests mitochondrial DNA mutations could be to blame for mum passing down Alzheimer's risk. Powering the cells, the mitochondria have their own set of genetic instructions which appear to be passed down directly from mothers. This increases the risk of any mutations in a mother’s mitochondrial genes being passed down to her children - mitochondrial dysfunction has proven association with brain differences contributing to Alzheimer’s disease. This theory also comes with the caveat that further research is required to substantiate the claim.

Looking at the research pointing to mum being responsible for passing down Alzheimer's objectively, it might not completely be her fault. Those responsible for the study agree that sociological influences could have impacted their findings - women generally live longer than men, and those taking part in the research might not have had fathers who lived long enough to develop the condition.

However, the study does has have strong evidence to suggest mum is more likely to pass down Alzheimer's disease, paving the way for researchers to find out more about the exact mechanisms for this to happen.

You might also like to read about how you're less likely to inherit your parents' personality than you think, and the 10 positive traits children learn from their parents. Traits aren't always inherited but can be influenced by upbringing, and we share the seven traits found in adults lacking affection as kids.