RESEARCH - Lupus not identical in twins

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January 16th, 2010; Vol.177 #2

By Tina Hesman

Lupus not identical in twins

Pattern of chemical tags on DNA linked to the autoimmune disease

Lupus can tell identical twins apart by the distinguishing marks the

pairs carry on their DNA.

Fewer DNA methylation marks may leave one twin vulnerable to the

inflammatory autoimmune disease, even while the other sibling remains

healthy, a new study appearing online December 22 in Genome Research

shows.

The finding suggests that environmental factors determine whether

genetically susceptible twins will contract lupus, or systemic lupus

erythematosus, which is characterized by the immune system attacking

the body’s own cells.

Researchers have previously identified at least 17 different genes

involved in lupus. If genes alone were responsible for determining

whether a person gets lupus, then every time one identical twin got

the disease, the other should too.

But that doesn’t happen. Between 40 percent and 75 percent of the

time, when one twin develops lupus the other stays healthy, indicating

that some environmental factor must trigger the disease, says Bruce

, a rheumatologist at the University of Michigan Medical

School in Ann Arbor.

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Read the entire article here:

http://www.sciencenews.org/view/generic/id/51410/title/Lupus_not_identical_in_tw\

ins

Not an MD