Researchers have discovered that a treatment involving enzyme-replacement therapy dramatically reduces the risk of death in children with Pompe disease, a rare genetic disorder, from which most children die before their first birthday. The disorder causes profound muscle weakness and heart and breathing problems and affects as many as one in 40,000 births. The study is published in the online edition of Neurology, the scientific journal of the American Academy of Neurology.

“This form of treatment has changed the natural history of this otherwise lethal disease,” said study author Priya Sunil Kishnani, MD, Duke University, Durham, NC.

The year-long study involved 18 children under the age of 6 months with rapidly progressing Pompe disease, which is caused by a deficiency in the enzyme acid a-glucosidase (GAA), needed to break down glycogen, a complex sugar molecule that releases glucose.

The study found all 18 children who started to receive the enzyme replacement, recombinant human GAA (rhGAA), before they were 6 months old survived to at least 18 months of age. Fifteen of the 18 children also did not need a ventilator. The study showed that starting rhGAA before the age of 6 months reduced the risk of death in children by 99%, reduced the risk of death or invasive breathing assistance by 92%, and reduced the risk of death or any type of ventilation by 88%, compared to past patients without this treatment.

“This form of enzyme replacement therapy markedly extended survival and improved respiratory performance in these children, with a majority of them showing normal growth and substantial gains in motor development,” said Kishnani. “rhGAA is safe and the only effective treatment for Pompe disease; it is life saving.”

Kishnani said the young age at which the children began treatment might have contributed to their improved response compared to previous trials with rhGAA, in which patients were older.

“This study demonstrates that starting enzyme replacement therapy early, which could be facilitated by newborn screening, shows great promise to reduce the mortality and disability of babies with this devastating disorder,” said Kishnani.

The most common side effects of the rhGAA treatment included skin reactions such as rash and hives, fever, and changes in heart rate.