'Genetic Defect Responsible for Rare Premature Aging'

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Genetic Defect Responsible for Rare Premature Aging Disorder Identified

By Ault

WASHINGTON (Reuters Health) Apr 16 - Scientists from the U.S. and France simultaneously announced on Wednesday the discovery of the genetic mutation that causes Hutchinson-Gilford progeria syndrome, an extremely rare form of premature aging.

The finding was hailed by researchers as extraordinary, since it took just under a year to pinpoint the gene.

Also, the gene could play a role in normal aging and in contributing to heart disease and stroke, said Francis , director of the National Human Genome Research Institute, and a contributor to the progeria gene hunt.

"What we learn about the molecular basis of this model of premature aging may provide us with a better understanding of what occurs in the body as we grow older," said at a press briefing.

Progeria has been hard to study since it occurs in only about one in four-to-eight million births worldwide, and only a few dozen children are alive with the condition at any given time, said Ted Brown, another progeria gene hunter and a geneticist at the New York State Institute for Basic Research in Developmental Disabilities.

Also, progeria is not an inherited condition, which has puzzled many scientists over the 110 years since it was first noted.

Children with the condition fail to thrive, leading to very short stature, loss of body fat and joint stiffness. By the time they are four or five years old, they look like a very old adult. With the premature aging comes heart disease and arteriosclerosis, making stroke and heart attack the leading cause of death in the children, who rarely live beyond adolescence.

The hunt for a genetic cause took off quickly after Gordon, a physician whose son was born with the disease, began a crusade in 1999 to fund more research. She convinced the National Institutes of Health to hold a workshop on progeria in 2001.

The researchers had some clues -- past studies of progeria children seemed to indicate an abnormality in a region of chromosome one. Their hunt was helped along by the continuing completion of the map of the human genome.

By October 2002, a consortium of NIH scientists and researchers from around the country had narrowed their search to a single gene, LMNA. Normally, that gene produces Lamin-A and Lamin-C proteins that help the cell nucleus hold all its contents during cell division.

In 18 of 20 children with progeria studied, U.S. researchers found a mistranslation of a single DNA base on the gene, which led to Lamin-A truncation.

Children with progeria have very misshapen cell nuclei, which likely leads to widespread cell death and premature aging, concluded lead author sson of the NHGRI in a paper announcing the gene discovery in the April 17th issue of Nature.

The French researchers reported the same findings in the April 17th online edition of Science.

Dr. Gordon of the Progeria Foundation said that the work "is a great springboard" from which to find diagnostic tests, treatments, and perhaps, one day, a cure for the condition.

Tests are just around the corner, said Dr. .

Nature 2003.

http://dx.doi.org/10.1038/nature01629

Science 2003.

http://www.sciencexpress.org