New Niemann-Pick Mouse Engineered
It is with good reason that Edward Schuchman calls Niemann-Pick Disease type A a “very, very challenging disease.” The neurodegenerative disorder is rare, kills those who have it by age 2 or 3, and has no known cure. But in May, Schuchman and his research team at Mount Sinai Medical Center in New York announced a breakthrough in their work on the disease.
There are three mutations that account for more than 90% of NPD-A cases among Ashkenazic Jews. Approximately one in 80 Ashkenazic Jews are carriers of the mutations that cause NPD-A.
The mutations that cause NPD-A affect an enzyme called acid sphingomyelinase and prevent the enzyme from performing its normal function of breaking down fats. As a result, fatty deposits accumulate in the vital organs, including the brain. Although a child who has NPD-A may appear healthy at birth, symptoms from the fat buildup typically show by six months.
The recent breakthrough came when Schuchman’s team at Mount Sinai’s International Center for Types A and B Niemann-Pick Disease successfully engineered mice with genes that express the mutant enzyme. Experiments that will attempt to enhance the activity of the malfunctioning enzyme are slated to begin in 2010. The researchers previously experimented on mice that were engineered to lack ASM, unlike human Niemann-Pick type A patients, who actually have the enzyme, albeit functioning improperly.
The new mouse, said Schuchman, “should be much more useful in research aimed at treating Niemann-Pick type A.”
There is currently no treatment for NPD-A. “We don’t yet have a therapy we think could work clinically,” Schuchman said.
Schuchman noted that an emphasis on prevention through genetic screening might have reduced the number of cases of the disease. “The Ashkenazi community is educated and aware of these diseases.” But, he added, “It doesn’t mean you stop doing research.”