Researchers have identified a defective collagen gene in awoman suffering from post-menopausal osteoporosis (PMO).
The finding, by scientists at Jefferson Medical College inPhiladelphia, suggests that at least a subset of women may beidentified to be at risk for PMO based on mutations in thegenes for Type 1 collagen.
Many companies, including BioGrowth, CaliforniaBiotechnology, Celtrix, Ciba-Geigy, Eli Lilly & Co., Genentech,Ligand Pharmaceuticals with Pfizer, Merck, Proctor & Gambleand Sandoz are developing drugs to address the multibilliondollar osteoporosis market. The ability to identify patients atrisk for PMO before bone loss occurs would allow doctors tobegin treatment earlier to ensure that bone strength ismaintained.
Osteoporosis leads to more than 1.2 million fractures eachyear in the United States. PMO occurs when a woman's bonedensity declines after menopause. About 20 percent of womensuffering from PMO have breaks in their vertebrae.
Collagen is a structural protein that provides the majortensile strength in bone. Mutations in collagen lead to theformation of bone that is susceptible to damage.
The Jefferson team previously identified Type 1 collagenmutations in patients suffering from the inherited diseaseosteogenesis imperfecta. OI, characterized by brittle bones,leads to multiple fractures at an early age.
The PMO mutation reported in this month's Proceedings of theNational Academy of Sciences is similar to OI mutations inthat it encodes a collagen protein that does not form normalbone. The researchers pinpointed the mutation to a singleamino acid substitution in the collagen that causes the proteinto fold incorrectly.
The researchers acknowledge that the symptoms of the PMOwoman are similar to those of patients afflicted with mildforms of OI. The scientists suggest that the two defects mayoverlap both genetically and symptomatically.
-- Carol Talkington Verser, Ph.D. Special to BioWorld
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