December 2, 2009
Canavan Disease: A Tale of Two Sisters

Like most parents, Dee and Jim White adored their daughter Carly. They reveled in every milestone she reached through infancy and toddlerhood at their Chatham home. But by the time Carly turned 3 in 2003, they were doing more worrying than celebrating. Her muscles seemed weak. She had trouble focusing her eyes. Perhaps most concerning, however, were the similarities the Whites saw in their younger daughter, Hanna.

Instead of crawling in the typical “all fours” position, the girls scooted along the floor on their bottoms. Neither walked until 19 months of age. And even as babies, both had eyes that drifted to the side.

With nothing more than these symptoms and a parent’s intuition, the Whites embarked on a medical odyssey that would span three years and more than 10 doctors before they finally learned the truth behind their girls’ ailment—and the remarkable fact that they’d won the equivalent of the genetic lottery.

Their quest took them to pediatricians, neurologists, ophthalmologists, and orthopedists. Dee kept a detailed spiral notebook, listing doctors’ names and appointment dates interspersed with milestone haircuts and Carly’s first signature. They tried to live as normally as possible, with Jim encouraging the girls in his passion for sports and a lifelong dream to visit every baseball stadium in the country.

Yet there were medical issues they just couldn’t ignore. The girls were diagnosed with low muscle tone. Carly had two eye surgeries, and both girls wore patches to strengthen their eye muscles. As they grew older, they began physical, occupational, and speech therapy. But a diagnosis still eluded them.

“The problem was, whatever specialist we went to, they figured it was something within their area,” Jim says. “They didn’t look at the bigger picture.”

It took Dee and her desire for another baby to finally crack the case. Realizing the girls’ health issues were too similar to be coincidence, she says, “I wanted to make sure we wouldn’t have more problems with low muscle tone in another child. So I asked for genetic testing.”

Finally, on January 26, 2005, the Whites received the answer they’d been seeking for years. Both of the girls had Canavan Disease.

“They have what?” was Jim’s initial response.

Rare & atypical
Like most people, the Whites had never heard of Canavan Disease. It’s a fatal, inherited neurological brain disorder in which the myelin that insulates and protects the nerves is destroyed by a buildup of acid in the brain. In typical cases, patients can’t hold their heads up, sit unassisted, or clutch a toy. As the disease progresses, a child’s head can grow abnormally large. Paralysis, blindness, and hearing loss may occur, followed by death, typically between the ages of 3 and 10.

Jim and Dee were devastated. Yet doctors were mystified. So mystified, in fact, they’d run the girls’ urine samples twice to make sure their diagnosis was correct. Carly and Hanna definitely had Canavan Disease, but their symptoms were anything but typical.

“When you look at other patients with Canavan Disease, 99.9 percent of them have devastating symptoms,” says Paola Leone. Leone, a PhD, is director of the Cell & Gene Therapy Center and associate professor of cell biology at the University of Medicine and Dentistry at New Jersey’s School of Medicine in Stratford. “So when I see the White girls I’m always amazed, and I cannot stop thinking how lucky they are.”

Jim recalls turning to the Internet for answers. “That’s when I had a breakdown. You start thinking you’re going to watch your child deteriorate in front of your eyes and die. How do you tell a kid who is 5 or 6, who is going blind, they’ll never see their mommy and daddy again?” Jim pauses, choking up at the memory. “As a parent, your job is to protect your kids and make sure bad things don’t happen.”

Clinging to the hope that their girls’ illness was atypical, Jim and Dee did their best to remain optimistic. “We realized we could look at the glass as being half empty or half full,” Jim says. “We decided to be half full.”

Meanwhile, doctors were eager to learn more. Canavan Disease is caused by genetic mutations, two commonly found in Ashkenazi Jews and one in people of Northern European descent. With ancestors from England, Scotland, Germany, and Italy, it was no surprise Jim had the Northern European mutation. Dee, with her Italian lineage, however, carried a mutation never seen before. “Dee’s mutation makes all the difference,” says Dr. Leone. “That specific and unique gene mutation is why the girls are fairly healthy.”

Playdates & siblings
Meanwhile, day-to-day life for the Whites changed little. The girls went to therapy and had playdates with friends. Doctors warned Jim and Dee to look for any deterioration or loss of previously acquired skills, but Carly and Hanna blossomed. Jim and Dee decided it was finally time to expand their family, and hoped for a boy.

Realizing each subsequent child had a one-in-four chance of inheriting Canavan Disease and a one-in-two chance of being a carrier, the Whites were understandably apprehensive. Luck, however, was with them on two accounts. Not only were they blessed with son James III in 2006, but tests revealed him to be negative for Canavan Disease. The family expanded again this year with the birth of Jennifer, who’s also negative.

Today life at the White household goes on. Carly, now 9 years old, is in third grade; 6-year-old Hanna is in kindergarten. While they are intellectually at grade level, fine motor skills such as handwriting and coloring lag behind. They receive extra help at school, continue with physical, occupational, and speech therapy, and are examined periodically by their various doctors.

Jim and Dee have not yet told them about their diagnosis. “They think the way we live is normal,” says Dee. “They don’t know there’s anything wrong with them.”

“Eventually, some day when they want to get married and have kids, they’ll have to know,” Jim says. “For now I try not to treat them any differently. I don’t want them to use it as a crutch for why they can’t do something.”

In fact, Carly and Hanna may be in a unique position to do something no one else can—to provide the key to a cure for Canavan Disease. “Without a doubt, the key to finding a cure is in the White girls’ genetic makeup,” says Dr. Leone.

She and her colleagues work with the sisters’ genetic material to determine which genetic or biochemical mechanisms are responsible for their good health, in hopes of recreating it in other Canavan patients.

Meanwhile, the Whites hope and pray for a cure for all the other children affected with Canavan Disease. Until then, Jim, Dee, Carly, Hanna, James, and little Jennifer will appreciate life, taking each day as it comes. And visiting a few baseball stadiums in the process.

 

Kristen Stewart is a freelance writer who specializes in health, parenting, and lifestyle topics. She lives in Cranbury, New Jersey.

Photograph by The Image Maker.

December 2009

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