Researchers Find Genetic Mutation Linked with Sturge-Weber Syndrome

Researchers have now found that a genetic mutation that occurs in the womb is the cause behind Sturge-Weber syndrome (SWS) and port-wine stain birthmarks.

SWS affects about one in 20,000 people, while port-wine stain birthmarks are quite common, with a million people in the U.S. having these birthmarks. Children born with SWS have glaucoma, intellectual impairment, port wine birthmarks on the face, seizures, paralysis  etc. Today, certain medications help reduce the likelihood of seizures and strokes in these children while glaucoma in the children is controlled by the use of eye-drops.

Port wine birthmarks occur in about 3 out of every 1,000 people in the U.S. and are a result of swollen blood vessels creating a purplish discoloration of the skin.

"This is a complete game changer for those with Sturge-Weber syndrome and the millions born with port-wine birthmarks. Now that we know the underlying genetic mutation responsible for both conditions, we're hopeful that we can move quickly towards targeted therapies, offering families the promise of new treatments for the first time," said Anne Comi, M.D., Director of the Kennedy Krieger Institute's Hunter Nelson Sturge-Weber Center and one of the senior authors of the study, according to a news release.

For the study, researchers analyzed affected and non-affected tissue samples from three people who had SWS. Researchers found one somatic mutation that was present in all the three samples. A somatic mutation is a kind of mutation that occurs after conception, and it affects only a part of the body. The somatic mutation in this case was a "nucleotide transition in gene GNAQ on chromosome 9q21."

Researchers then confirmed the findings by analyzing 26 samples from SWS patients, of which 23 had the same mutation and 12 of 13 people with isolated port-wine stain birthmarks. None of the tissue samples from people without the condition had this mutation.

Also, the research showed that the mutation linked with SWS and port wine birthmark is also linked with a cancer of the eye called uveal melanoma.

The finding of gene and the responsible pathway for condition can enable researchers to discover drugs that can affect the pathway.

The study is published in the New England Journal of Medicine.