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The genetics of FTD. Do you want to know?

When Robert was first diagnosed with frontotemporal dementia (FTD) in 2017, I did what most people do when faced with a shocking, terminal diagnosis. I jumped into research to try to uncover snippets of hope in the looming ruination of our lives. My investigation focused on two questions: What can we do to stop or slow Robert’s disease progression? What might Robert have done differently to avoid this fate?

The questions we ask

The first question is about salvation. Desperate, hopeful, and ultimately tragic (because there is no good news), this question is about rescuing Robert from the horror of this disease; and rescuing the rest of us, his family.

The second question might seem like victim blaming, but at its core, the subtext of the question is this: How can I be sure this won’t happen to me?

Of course, we all ask the first question. We want so desperately to help our loved ones.

Why this will never happen to me

And I’m just as sure most of us play out some version of the second question in our minds when we learn of the life-threatening diagnosis of a family member or friend. We look for behaviors and circumstances that differ from our own. This couldn’t possibly happen to me because “I don’t,” “I never,” “I haven’t…”

“He smoked for years.” 

“She ate red meat with every meal.” 

“He never did cardio.”

“She ate too much sugar.” 

“He lived near an oil rig in Torrance.”

“She drank like a fish.”

“He grew up in Toledo with bad water from Lake Erie.”

You’re not as smart as you think you are

The explanations we conjure are myriad and fruitless. So many environmental and behavioral factors influence our health, we cannot possibly point to a single defining characteristic that predicts disease in any given person. And there is no control group. We are, quite literally, one in eight billion.

Yes, some disease clusters point to fairly certain disease causation, but in the random presentation of disease, it is nigh to impossible to say with authority that factor X caused disease Y. Disease often presents sporadically.

Indeed the roots of FTD can be lumped into two categories: sporadic and genetic.

The vast majority of FTD cases, 80-90%, are sporadic, meaning there is no disease pattern in the family. I could find no smoking gun and no explanatory causes in my research on sporadic FTD. Medical science hasn’t unveiled a set of ingredients that predict the disease when it seems to pop up out of nowhere. Bottom line, there is nothing we can do to avoid an FTD diagnosis.

But what about his genes?

Initially, I completely ignored the genetic roots of FTD. The numbers are so small. Robert is one of 5 siblings, the middle child. None of his sisters or his brother exhibited any signs of disease.

But over time I stumbled across studies focused on treatments for the genetic causes of FTD. There are several genetic mutations linked to FTD.

Genetic FTD is autosomal dominant. Children of a person with genetic FTD have a 50% chance of inheriting the gene that causes the disease. If the mutated gene is inherited, the child will also develop FTD. These are very poor odds indeed. (There are a few, very rare exceptions to this outcome.)

Hoping for a better future

If, one day, there is a treatment for a genetic variant of FTD, wouldn’t you want to know if you are a carrier of the genetic mutation that causes the disease?

The more I dug in, the more determined I was to have Robert tested. There is no cure for his disease. But what if he does carry a gene mutation? Could we save our kids his fate?

My thought process

My decision to pursue genetic testing was deeply personal and fraught with landmines. These are the points I considered. 

Robert could be tested and the results of his testing would not be linked to his children. At least not today. Why is this important? Genetic information could be used to discriminate against our children. 

Title II of the Genetic Information Nondiscrimination Act (GINA) of 2008, prohibits the use of genetic information in hiring decisions. The law more broadly prevents employers and other entities from requesting, requiring, or purchasing genetic information, and strictly limits the disclosure of genetic information. 

But the existence of the law suggests the specter of a breach has already materialized. How long before insurance companies successfully lobby for genetic information to protect against “catastrophic losses?” 

If a genetic cause of Robert’s FTD was found, our children could choose whether or not to be tested.

Knowledge is power. You can’t pursue treatment if you don’t know you have the genetic mutation that will cause the disease.

But first genetic counseling

To start the process, I was required to meet with a genetic counselor. We talked about Robert’s family history, as much as I knew anyway, and based on the fact that none of Robert’s siblings had shown any signs of disease the counselor was reasonably certain no genetic link would be uncovered.

I wasn’t so sure. Robert was one of five surviving children, that was true. With an autosomal dominant gene, one or two of his siblings should experience some disease manifestation if the cause was a mutant gene. But there had been seven pregnancies in total, not just five. Robert plus the two who were lost would have met the 50% mark. Robert’s mother had died at 62 and may not have lived long enough for the disease to express itself. (Present me with ironclad reasoning, and I’ll burrow into the wormhole where the corner case of bad news hibernates.)

I was warned that if a genetic link to Robert’s FTD was uncovered, I could never unknow this. 

I was advised that genetic information while protected under GINA was not necessarily secure. At some point in the future, this information might legally be used to deny an application for life insurance, for example.

What are your intentions?

The counselor asked questions that explored my intentions. Had I talked with my children about the testing? What would I do if the tests showed a genetic link? Most critically, the panel of tests to be used on Robert look for sixty genetic markers for dementia we know about today. Others may be uncovered in the future. The absence of a genetic link  today is not an “all clear.” Scientists make new discoveries all the time. 

I had not talked with the kids about the testing. In a corner of my mind, I thought, “Well, if a genetic cause is found, I don’t have to say anything to the kids today. I can wait until a treatment is found.” My rationalization was truly heroic! Did I really think I’d monitor all the science around FTD forever? Did I really think I wouldn’t worry about my children for the rest of my life? Would I share the bad news on my deathbed?

The counselor’s questions gave me pause, but I pushed forward with my decision to pursue testing. 

I told Maddie and Trent that Robert would be tested. They were philosophical about the prospect. We know so little about what lies in our future. Trent said he would love and cherish Maddie no matter what happened. He touched me so with his commitment and kindness.

I didn’t tell Jackson about the testing though. He is ten years younger, in his early 20s, losing his father too soon, and in the middle of his graduate studies; I didn’t want to throw him another curve ball. 

Getting tested

Robert’s blood was drawn on a sunny September morning in 2021. (I managed to get him into the car to take him to the clinic, but couldn’t get him out. A phlebotomist came outside and drew his blood through the passenger side window.) In four weeks, I’d get the results.

My mind ticked down the days. The test results weren’t in the front of my mind, but I did find myself distracted at times, staring off into the distance thinking about what might come.

About a week before the results were due, I felt this overwhelming panic. What in hell was I thinking?! I couldn’t know this! I couldn’t live with more bad news. I considered reaching out to the geneticist managing Robert’s case to call off the “big reveal.” The test results could sit unexplored forever.

In the end, I staunched my frayed nerves and learned the results. 

There is no genetic link to Robert’s FTD.

His disease is sporadic, a random occurrence in a world of chances.

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