A Hypomyelination Story

Aaron Hardy
Published in
10 min readOct 24, 2019

I originally wrote this on November 5, 2015, when our daughter Brinley was six years old. I shared it on Facebook and am now sharing it with the rest of the world. Brinley is now ten years old. Most everything described below still applies; she’s just older and bigger now with a newer set of spinal rods and on oxygen 24/7.

With all that’s been going on with our daughter Brinley, I’ve had a lot of people ask about her condition and background. Since Brinley is now sleeping soundly I figured I would take a moment to write it up. I do this so others might learn. Maybe it will help diagnose a child someday. Maybe it will help others through hard times. Maybe it will satiate some curiosity. Whatever the reason, you’re invited to read if you so desire. Should you choose to accept, beware that it is a long read and a bit detailed at times.

Brinley shortly after birth

Brinley had a bit of a rough start to life. During delivery the umbilical cord was wrapped around her neck and she was aspirating meconium. This was a cause for concern but was successfully resolved in relatively short order with no long-term effects. However, less that two week later, Brinley was admitted back into the hospital with a severe UTI that required some heavy-duty treatment. Once the UTI was resolved, the first few months of her life were relatively normal for a baby of that age. It was difficult for her to breastfeed and she had acid reflux but nothing that seemed too out of the ordinary. She did cry a lot, which, in retrospect, was much more than typical for other infants.

At a few months of age, Brinley’s eyes started to be noticeably crossed. We took her to the optometrist who suspected the crossing was due to an imbalance in eye muscles and she went through surgery to get it mostly fixed. However, Brinley also developed nystagmus where her eyes would involuntarily bounce vertically. Nobody could identify a cause.

Once we started introducing solid foods to Brinley, she had a really tough time eating. She kept choking whenever we put food in her mouth and it seemed as though we spent most of our day trying to get her to eat a sufficient amount. Most noticeably, Brinley really struggled holding up her head and wouldn’t make much of an effort to roll over or crawl. During Brinley’s checkups, the doctor chalked it up to general developmental delay. Being new parents, we didn’t know any better, though our relatives were suggesting that some other variable might be involved.

When Brinley was six months old, my sister Jennifer, who has a disabled child of her own, was doing some research and found a disease with similar symptoms. I believe it was a type of brain cancer that required immediate attention for successful treatment. Not wanting to deal with the uncertainty any longer, we drove up that night to Primary Children’s Medical Center in Salt Lake City and booked her into the emergency room. The attending physicians were a bit reluctant to do much because they too suspected general developmental delay. We told them we weren’t leaving without a better answer. After initial tests and some pleading on our part, they decided to order an MRI.


The MRI clearly showed, at least to the trained eye, a lack of myelin. Myelin is the white coating on the brain, also known as the myelin sheath, that insulates neurons. Just like a ball of wires without any coating, a brain with a lack of myelin means signals have a hard time traveling to and from the rest of the body.

I distinctly remember when the team of doctors came into the hospital room to reveal the news. I was relieved! She didn’t have the precarious disease my sister had found. Naively, I figured we just needed to order some medicine, go home, and Brinley would be eating and crawling a few weeks later. It wasn’t until the doctors left the room and I asked the internet about it that reality started to kick in. Life was going to change.

When people ask what disease Brinley has, we typically respond with “hypomyelination”, or in other words, less-than-normal myelin. It falls within a group of disorders known as leukodystrophy, or in other words, a disorder of the white matter of the brain. We now had a name and we knew she had insufficient myelin, but we didn’t know why she had insufficient myelin. We wouldn’t know the answer for four more years.

There are probably hundreds of potential underlying causes of hypomyelination, each with their own particular set of symptoms, mortality rates, and hereditary properties. Sometimes children with deteriorating myelin are living a normal life and then start to regress into having difficulty speaking, then difficulty walking, then difficulty crawling, and so on. Some improve over time as they grow additional myelin. Some children can walk and talk quite well while others can’t breathe on their own. Some live many years while others die early on. Some families have multiple children with the disease while others do not.

Over the years, Brinley underwent a plethora of tests (or as the doctors called it, “an extensive diagnostic odyssey”) and each time they returned normal. These tests included, among others:

Chemistry 10 panel
Complete blood count
Liver function testing (AST, ALT, GGT, Albumin, Bilirubin)
Thyroid testing (TSH, FT4)
serum amino acids
urine organic acids
urine homovanillic acid
urine vanillymandelic acid
leukocyte lysosomal enzymes
urine sialic acid
transferrin isoelectric focusing
comparative genomic hybridization microarray
GLC2 gene sequencing
PLP1 gene sequencing

The geneticists and neurologists we saw were stumped and found her case to be quite unique. Unique enough, in fact, that when Brinley was four years old they found sufficient value in researching her case that they managed to secure a grant to perform DNA sequencing and publish a medical paper with their results. It was titled Clinical Exome Sequencing Identifies a Novel TUBB4A Mutation in a Child with Static Hypomyelinating Leukodystrophy.

I remember in junior high learning about how someday we would have the computing power to sequence the human DNA and use it to discover the cause of diseases. Little did I know my daughter would be one of the first beneficiaries of this powerful technology.

The results of the DNA sequencing showed that Brinley had a mutation in the TUBB4A gene which causes hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). There were 22 known cases of this in the world as of 2013. The doctors also concluded that we had no greater chance of having another child with this disease than anyone else; it was a seemingly random occurrence. By that time, Holly and I had already rolled the dice and had a son who did not have the same disease. There is no cure for the disease at this time.


Brinley’s disease affects all senses. If it’s bright outside, she keeps her eyes shut and sneezes almost immediately. If it’s hot, she gets really hot. If something stinks, she gags or vomits. One time we drove past a feedlot and it was enough to cause her to vomit in the car. If my brother-in-law yells loudly at the TV during a football game, she’ll tense up and possibly cry depending on the level of vulgarity. If we put anything near her lips she’ll stick out her tongue and make a bitter face. If she touches anything with an odd texture like the plastic grass in an Easter basket, she’ll do her best to pull her hand away.

Brinley’s disease affects all parts of her body. She doesn’t hold her head up, sit, crawl, walk, or roll over. She has what the medical field calls hypotonia, more affectionately known as floppy baby syndrome. She’s floppy. Even so, if she’s really excited or really mad she can throw out her arms and legs with a surprising amount of force.

At about a year and a half old, she wasn’t getting the calories needed orally so we had a gastrostomy tube (G-tube) placed so she could get what she needed through a tube. A G-tube delivers formula directly into the stomach. At first, this seemed to work quite well, but over time, it became obvious that Brinley was malnourished. She was vomiting the formula faster than her body could absorb it. At just under three years old, she had her G-tube switched out for a gastrostomy-jejunostomy tube (GJ-tube). This allows us to deliver formula to either her stomach or her small intestine. By delivering it to her small intestine, it prevents her from vomiting it and allows her body to get the calories she needs. She now receives all her formula and medication through the jejunal port. Brinley’s digestion is also messed up so we try to keep it flowing as normally as possible through medication.

Most critically, swallowing, breathing, and coughing are difficult for her, making her particularly susceptible to respiratory illness. She uses oxygen at night. She vomits several times per day due to secretions (not food) that get trapped in her throat, lungs, and stomach. Although it’s not a pretty sight, in my opinion it’s easier to stomach than your average kid’s spaghetti-and-meatball projectile vomit. Brinley’s health largely hinges on keeping her airways clear and functional.

Which leads us to our current hospital stay. Over the last couple years Brinley has developed severe scoliosis which, according to her surgeon, measured around 110 degrees. At this angle, her spine is basically all the way to her side which forces her hip to tilt and put pressure against her ribs. This not only results in pain, but also a malformed ribcage and a lung that can’t fully expand. Other organs can also be affected. For a few years now she has worn a custom-fitted back brace that acts as an exoskeleton while she sits up. While this helps, it’s hot, uncomfortable, and ultimately unsuccessful at preventing her scoliosis from progressing. To address the issue, we chose to have spinal rods placed in her back which aid in keeping her hips aligned with her shoulders. It’s an invasive surgery that took about five hours to complete including setup and teardown. It consists of placing two rods that attach to her top ribs and her pelvis. If you can stomach it, here’s a video of the procedure (it’s not Brinley in the video). The surgery itself has corrected the angle of her spine by around 40%. Over time we may be able to squeak out a bit more than that.

X-ray of Brinley’s spinal rods

As kids grow, the spinal rods need to be extended. In the past, this involved sedating the child every six months or so and making incisions to get access to the rods to adjust them. Fortunately, new technology has come along and allowed us to elect MAGEC spinal rods which can be adjusted periodically with the power of magnets — no incisions necessary. This is a huge benefit and we’re really excited this is an option. As Kip would say, I love technology.

In my conversation with others, I’ve noticed a few recurring questions:

Does she talk? No, she doesn’t talk, but she definitely communicates. She laughs when she thinks something is funny, she whines when she doesn’t feel good, she cries when she’s sad, she smiles when she’s happy. She tries to sing songs with us. She tries to talk to me every time I come home from work. She’ll be very cautious (typically staying still while keeping her eye on her surroundings) when she’s in a new environment or around new people. She’s learning to look at the thing that she wants when given two options.

Does she understand? She understands a lot but it’s hard to say just how much. She is definitely aware of what’s going on around her and understands concepts. She’ll pick up on Mom getting ready to leave without a word being said and lets us know about it. She has things she likes and others that she doesn’t. When we talk about things like going on a walk, going to sleep, reading books, or playing with her brother, she knows what we’re talking about and responds accordingly.

Do we know how long she will live? Not really. When we initially found out about her disease the doctors said Brinley may live days, months, or years. They knew so little about the disease that their guess was as good as ours. Her myelin is neither receding nor growing (except for a small amount in one specific spot) and her health is generally stable enough that doctors now think she should be able to make it into her teenage years. Typically it’s pneumonia or some other respiratory illness that takes the lives of children like her so it primarily comes down to how many of those illnesses she can make it through.

How does she deal with the hardships? She’s amazingly patient. One thing that always has impressed me about Brinley is that she can go from sad to happy in two seconds. She enjoys the good times with disregard to difficulties in her past even when those difficulties were extremely recent and taxing. She gets frustrated and anxious, but she never seems mad at anyone. I can’t imagine her holding a grudge. She does an incredible job of enjoying life through the struggles. It’s a very rare occasion when I can’t get her to laugh. I learn a lot from how she handles life.

There you have it. Now you know way more than you ever wanted to know. We love our Brinley and hope she sticks around for years to come.

To learn more about what it’s like to be a parent of a disabled child, check out my wife’s blog, Living the Special Life.



Aaron Hardy

I am a software engineer at Adobe working on the Adobe Experience Platform Web SDK. I am a fan of documentaries, podcasts, and bikes.