Children eating 311.
(photo credit: Dudu Azoulay)
A team of scientists, led by researchers at the University of
California, San Diego School of Medicine and Zacharon Pharmaceuticals, have
developed a simple, reliable test for identifying biomarkers for
mucopolysaccharidoses (MPS), a group of inherited metabolic disorders that are
currently diagnosed in patients only after symptoms have become serious and the
damage possibly irreversible.
MPS is caused by the
absence or malfunctioning of a lysosomal enzyme required to break down and
recycle complex sugar molecules called glycosaminoglycans, which are used to
build bone, tendons, skin and other tissues. If not degraded and removed,
glycosaminoglycans can accumulate in cells and tissues, resulting in
progressive, permanent damage affecting appearance, physical abilities, organ
function and often mental development in young children. The effects range from
mild to severe.
There are 11 known forms of MPS, each involving a
different lysosomal enzyme. A number of treatments exist, including enzyme
replacement therapy and hematopoietic stem cell transplantation, but efficacy
depends upon diagnosing the disease and its specific form as early as possible.
That has been problematic, said Jeffrey D. Esko, PhD, professor in the
Department of Cellular and Molecular Medicine and co-director of the
Glycobiology Research and Training Center at UC San Diego.
time from seeing first symptoms to diagnosis of MPS is about three years. Since
the early signs of disease are common childhood issues like ear infections and
learning disorders, the disease is usually not immediately recognized,” Esko
“A child often has multiple visits with their pediatrician.
Eventually they are referred to a metabolic disease specialist, where rare
diseases are considered. It takes an expert to identify MPS and its most likely
form in each patient. Every subclass of MPS has its own specific diagnostic
test, so developing better diagnostics is an essential part of effective
treatment. ” In their paper, the scientists describe an innovative method to
detect tell-tale carbohydrate structures specific to glycosaminoglycans in the
cells, blood and urine of MPS patients. The biomarker assay identifies all known
forms of the disease.
Esko is collaborating with Zacharon
Pharmaceuticals, a San Diego-based biotechnology company, to develop a
commercial diagnostic assay for differentiating forms of MPS from urine and
blood samples, a screening test for newborns and a tool for measuring the
biochemical response of MPS patients to existing and novel
“Since the severity of the disease is highly variable among
patients, this could provide a tool that a doctor can use to optimize dosing or
treatment,” said Brett Crawford, Vice President for Research at Zacharon.
“Currently, all patients are treated with the same dose of drug.”
biomarker test may also be used to discover new forms of MPS and better
characterize existing ones.
This article was first published at www.newswise.com