For nine years researchers have known the precise genetic flaw that causes Batten disease. But understanding how a straightforward mistake in life's blueprint translates to a disease that ravages roughly 1,000 children in the United States each year has been a challenge. Now, in a paper in the Dec. 23 issue of the Proceedings of the National Academy of Sciences, a team from the University of Rochester Medical Center lays out the sequence of biochemical steps that results in the disease.
The team led by David A. Pearce, Ph.D., of the Center for Aging and Developmental Biology found that the genetic defect is linked to a protein that regulates the amino acid arginine in and out of a yeast organelle called the vacuole. The vacuole in yeast is much like the lysosome in human cells, slicing and dicing up cellular waste and then disposing or recycling the material. In Batten disease and other lysosomal storage disorders, the lysosomes don't work correctly and cells swell up with gunk that eventually kills them.
Pearce's team found that the trouble with arginine levels is critical to throwing the pH levels of cells in lysosomes out of whack, affecting a range of processes and ultimately ruining a cell's ability to get rid of its own waste.
"It's a little bit like getting sugar in your gas tank," Pearce says. "Once you change the mix just a little, it has drastic repercussions throughout the system."
Children with Batten disease are born healthy, but often, around age 4 or 5, the first symptoms appear as a minor problem with a child's eyesight. Subsequently the malfunctioning lysosomes result in the death of more and more brain cells, and patients are beset with a host of medical
'"/>
Contact: Tom Rickey
trickey@admin.rochester.edu
585-275-7954
University of Rochester Medical Center
28-Jan-2004