The Nye Family’s Experience with Citrate Transporter Disorders and SLC13A5

The Nye Family’s Experience with Citrate Transporter Disorders and SLC13A5

by Kim Nye

My husband, Zach, and I live in Menlo Park, California with our four kids. Two of our four children have SLC13A5 mutations.

Growing up, adversity was a word we were lucky enough to not know. My husband and I went to high school together and then college together. We were married after we graduated from college, and headed to England for graduate school. While living in England, we found out we were expecting a baby girl. After a relatively easy and uncomplicated pregnancy, we welcomed our beautiful daughter Tessa into the world on December 22, 2003. I was 23 years old.

As first-time parents, we felt fairly clueless about normal newborn behavior, but it was clear to us that something might be wrong with Tessa when she turned blue during her first bath. She was also having trouble feeding. She would latch on, but could not coordinate breathing and eating simultaneously. She also seemed too strong for a newborn. By the time she was 24 hours old, she was in the NICU and arching and desaturating regularly. Tessa was having seizures.

All of Tessa’s labs and tests came back normal. There were no signs of infection or structural damage. Her brain MRI was normal. Doctors thought that perhaps she had a slight stroke or birth trauma, but they thought her prognosis was great. We were relieved and hopeful, but we could never quite get Tessa’s seizures under control. Doctors prescribed Phenobarbital, then added in Phenytoin. Because Tessa’s seizures started in her first day of life, we started Pyridoxine. Soon we were on a rollercoaster of seizures (focal, generalized, complex partial, tonic clonic, myoclonic) and seizure medications (Tegretol, Lamictal, Depakote, Topamax, Keppra, Felbatol… The list went on and on).

Tessa’s development seemed on track for her first six months, but then her gross and fine motor skills started to fall behind (sitting was especially hard for her to master). Tessa started speaking at a typical age, but then her speech started to fall behind too. It was absolutely heartbreaking for us to watch as our sweet and vibrant daughter’s health and development seemed to be slipping away. She seemed so close to being a typical baby, and yet we were constantly rushing to the ER after a large seizure. Our days were filled with endless OT, PT and Speech Therapy appointments. We had PET scans, MEG scans, more MRIs to see if surgery was an option. Tessa had a Vagal Nerve Stimulator implanted. We tried the Ketogenic Diet. We could not find that magic bullet.

We had a full genetic work up, and again everything seemed normal. There was no history of epilepsy or developmental problems on either side of our families. Our team thought that if this was genetic, it was likely a de novo genetic mutation. In other words, our chance of having another child with a seizure disorder was incredibly unlikely.

And our geneticists seemed to be right. We moved back to California, and in 2007 and 2009, we welcomed happy, healthy little girls into our family. We continued to stay up-to-date on the latest genetic tests, and we stumbled on a combination of medications (Felbatol and Diamox) that stopped Tessa’s larger seizures. Tessa continued to have hundreds of myoclonic jerks daily and her speech was severely delayed, but she was stable enough to go to school and run around with her sisters. As her receptive language is very strong, we bought her an Augmentative Communication Device so that she could boss us around.

We decided to have one more child. After another uneventful pregnancy, we welcomed our first baby boy! Colton was born on August 26, 2013. He looked just perfect. My husband and I thought we were the luckiest people in the world. We were now experienced parents in our mid-thirties, fully settled with a house and careers. And we got to have the big family we always hoped for. The delivery had gone well without complication, and Colton was doing all the things babies do: nursing, crying, sleeping. Our family was complete.

But at some point in the middle of that first night, our world came crashing down. Colton would latch on to the breast but not continue nursing. He started arching his back and turning a bit blue around his mouth. Colton was having seizures. My heart broke all over again. Only this time, I found it hard to have hope; I knew this disease all too well. I immediately jumped to the future. Instead of dreaming of football pads and college applications, I was wondering if he would ever speak. Instead of hoping that he would be tall like his dad, I was wondering how I would physically care for a disabled grown man. I bargained and pleaded with whoever would listen: Please just let my baby be okay.

Colton is not okay. He is adorable and smiley and opinionated, but he is not okay. His seizure control has been considerably better than his sister’s was in her first year, but he is lagging behind in his gross and fine motor skills. At 10 months, he is still not sitting well. He has strange episodes during which half his body goes limp.

But after more than ten years, we now think we know why two of our children suffer these episodes: SLC13A5, a citrate transporter disorder.

Unbeknownst to us, my husband and I are both carriers of SLC13A5 mutations. Tessa and Colton were unlucky enough to inherit a bad copy from each of us. And our geneticists couldn’t diagnose Tessa until now because our kids are among the first in medical literature to have this disease.

We hope that by sharing our story, we can connect with other families who have citrate transporter disorders. We hope that by shining a light on this new disorder that other families will be pulled out of the dark days of not having a diagnosis for their child. We hope that treatment options for our children and others like them are on the horizon. We hope to kick SLC13A5’s butt. Please help by sharing your story or connecting with our team.