A link to autism helps a relatively rare genetic mutation get attention
Researchers around the country are holding their buckets under the federal government’s stimulus package faucet that opened back in February. One of the many scientific priorities for the funding is a disease called Fragile X. The name might not be as familiar as autism, but the gene behind Fragile X is a major cause of that disease and others. [Maiken Scott contributed to the reporting of this story.]
Matthew Hollin is a charming sixteen year old with a love of Map Quest, a stack of medals from track and swimming competitions, and a stretch of his DNA with molecules that repeat over and over and over.
Finucane: Cytosine, guanine and guanine, CGG, CGG, that’s the code.
Brenda Finucane is a genetic counselor at Elwyn, a behavioral health center in Delaware County.
Finucane: Typically people have anywhere from five to maybe 60 of these repeats…And in people with Fragile X in this syndrome they have over 200 of these repeats in a row.
These repeats interfere with the function of a gene. In Matthew Hollin’s case they caused cognitive disabilities and what his mom refers to as — a flavor of autism. But when Cristy Hollin was first noticing that something was different about Matthew, he was just a baby, little was known about the genetics of Fragile X.
Hollin: The first things I would notice is he wouldn’t reach up for us in the crib when we came over to get him out of the crib.
Then, he wasn’t sitting up on his own, or pulling himself to standing.
Hollin: Somebody suggested that we do a Fragile X test because Matthew had some interesting symptoms associated with Fragile X like hand flapping is a big one and kicking his feet out.
Around the same time as Matthew’s diagnosis, scientists were identifying the genetic cause of Fragile X. As you might have guessed, it’s on the X chromosome. Females have two, males have one. Boys tend to have more severe symptoms, because girls’ second X chromosome can compensate for the mutated one. Hollin was able to trace it throughout her family.
Hollin: I happen to have two adult cousins who have Fragile X. They weren’t diagnosed until after Matthew was diagnosed.
Finucane: It’s become realized this is not some obscure genetic disorder. This is actually the most common hereditary reason for mental retardation.
Brenda Finucane says the mutation can affect people’s health even beyond that condition.
Finucane: In recent years it’s been found that people who carry this gene and don’t have the full syndrome can also have a whole host of symptoms like infertility and atypical Parkinson’s disease.
About 100,000 people have the full blown syndrome; more than one million have these associated disorders. Not a huge number as far as diseases go. But there’s a link to one disease that’s catapulting Fragile X’s stature. Robert Miller the executive director of the National Fragile X Foundation.
Miller: With the huge rise in the country’s interest in autism, Fragile X is also been risen along with that because it’s one genetic explanation for autism.
About four percent of autism diagnoses can be traced back to those fragile X repeats. Money spent on research reflects the growing relevance of Fragile X. Funding doubled from the Centers for Disease Control and Prevention and went up about 20 percent from the National Institutes of Health in the last two years. Miller expects new therapies to shake out from this increased attention. And the Foundation is galvanizing a network of behavioral health centers like Elwyn and its pool of patients to help companies with clinical trials.
Miller: There’s no place in the world where they could go where there’s a sufficient number of patients to test this drug on. But when you take all of the members of the consortium, the 20 members, then you have a patient base instead of dozens or maybe 100, you now have thousands of people.
There is currently no cure for Fragile X. But at least 17 human experiments are ongoing to try and get there.