Treatment Developed At Duke Gives Families Hope Against Rare Genetic Disorder

As a teenager, Abby Phelps thought she was just a weakling. Most kids her age could climb on a horse's saddle, but she usually had trouble.

"My dad was trying to get me up on the saddle and he said, "Where are your muscles?" Phelps said.

Phelps said her muscles only got weaker. She said she started falling and getting injured. For years, Phelps and her older sister, Marty Phelps, did not know what was wrong. Finally, tests showed they had Pompe disease.

The blood lacks an enzyme that converts a starch called glycogen into sugar. The starch builds up in muscle tissue, including the heart.

"It also affects the muscles of breathing, which means that ultimately these patients do require breathing support via a ventillator," said Duke geneticist Dr. Priya Kishnani.

Duke developed a special enzyme replacement therapy. Clinical trials focused on babies born with Pompe. They usually do not survive their 1st birthday.

Two years ago, the Myozyme treatment helped Yamila Romero Jimenez celebrate her 1st birthday with improving health and development.

"This, clearly, is a life-saving therapy for patients with Pompe Disease," Kishnani said.

After approval from the Food and Drug Administration, Abby Phelps and her sister were first on a list of adults to begin the bi-weekly intravenous therapy. Both women would have begun treatments a week earlier.

"She passed away last Wednesday, the very day she was to come here. She fell in the shower and died of respiratory failure," said Abby Phelps.

Now that there is an approved treatment, doctors are pushing for better screening to identify children born with Pompe Disease.