Archive Opinion The Orion

Unraveling the genetic mystery of Fragile X Syndrome

January 1, 2007

The eggs were all hidden in the grass, waiting for the youngest kid in our family to find them. This wasn’t her first egg hunt this Easter, but it was the first with eggs she could actually hatch.

Whether it was when she was dyeing the eggs with her cousins or looking for them at the church, she had the same goal all weekend.

“I’m going to hatch the eggs and make babies come out,” she said.

It’s hard to believe that this is the same child who rarely put together a complete sentence, much less spoke. But we knew last year she was more than a shy 3-year-old.

We knew before she was born that Taylor had the full mutation of a common condition few people know about.

Fragile X Syndrome in its full mutation form can cause developmental delays, learning disabilities and emotional problems. It’s closely linked to autism, as 30 percent of people with the full mutation also have full autism, said Dr. Randi Hagerman, medical director of the Medical Investigation of Neurodevelopmental Disorders Institute at UC Davis.

The condition is caused by a trinucleotide repeat. People without Fragile X typically have five to 45 repeats. Carriers have 55 to 200. The full mutation happens after 200 repeats, when the gene becomes methylated and stops sending its message.

Think of the whole sequence like a sentence and each repeat is a word. The shorter the sentences, the more likely someone will understand it. As sentences get longer, people’s attention spans begin dropping off until finally the message is lost.

The full mutation can be found in about 1 in 3,600 people. More common and harder to spot are the carriers with the premutation. One in 130 women and one in 800 men are carriers who have their own set of subtle issues to deal with, Hagerman said.

The premutation can cause emotional problems such as anxiety and mood instability. About 20 percent of women with the premutation can have early menopause, some in their 20s. In older people, it can cause tremors and ataxia, which are commonly misdiagnosed as Parkinson’s disease and dementia.

Those misdiagnoses are common mainly because Fragile X isn’t something doctors look for specifically. If you aren’t looking for it, then it’s easy to miss, because the symptoms can be explained away by similar diseases.

Hagerman recommends that before visiting a doctor to talk about Fragile X, you should read up on the disease and bring some information to your doctor, who may not know much about it.

Before Taylor was born, I didn’t know Fragile X existed. While our entire family braced for the worst-case scenario, it’s hard to tell there’s anything remotely wrong with her. On the outside, she’s a perfectly normal 4-year-old.

Most of the problems she has related to Fragile X have been eased by the fact we were able to prepare for what was coming. We found out about it through amniocentesis before she was born. However, that was only because her mom’s family had a history of it and specifically asked to have her checked for it.

In the near future, Hagerman hopes that will change. She is working on a grant through the National Institute of Health that would help fund blood test screening for newborns to identify Fragile X patients who wouldn’t otherwise know about the condition.

Early discovery plays a large role in treating Fragile X. If we didn’t start working with Taylor early, we’d still be wondering what was going on in her mind while she wasn’t talking.