Fragile X 101

It's here!

During Fragile X Awareness month in July, the National Fragile X Foundation has published a month's worth of facts :)

Although I have neglected to post daily, I have condensed the list for my blog... & slightly catered certain portions to our personal experience.

Please take a few minutes to read these incredibly interesting facts about fragile x! 

Fragile X encompasses a group of conditions-- that's right, it is not just one!
There is:

• fragile X syndrome (FXS)

• fragile X-associated tremor/ataxia syndrome (FXTAS), usually present in male carriers

• fragile X-associated primary ovarian insufficiency (FXPOI), prevalent in female carriers 

The gene responsible for Fragile X is called FMR1 and is found on the X chromosome.

Everyone has the FMR1 gene on their X chromosome! But of course there is an interference with it, in people with Fragile X.

The FMR1 gene was identified in 1991. The FMR1 gene makes a protein (FMRP) important for brain development. People with fragile X syndrome have a deficiency of this protein.

Changes, or mutations, in the FMR1 gene are what lead to developing one of the Fragile X conditions.

These mutations are defined by the number of breaks, or repeats, seen in the DNA. The “normal” range for most people is around 50 repeats (give or take). The number of repeats for people with FXS is more than 200, & can exceed 1,000! 

FXS is a spectrum disorder. However, regardless how high the gene expansion is, this does not necessarily mean that a person with FXS is more affected; unless, as a geneticist once told us, the repeats are over 1400.

Fragile X is diagnosed through a DNA sample, most typically from blood, but amniotic fluid & other tissues can also be tested.

Hayden tested positive for fragile x syndrome when he was 17 months of age. His pediatrician at the time referred us to a pediatric neurologist, & the neurologist ordered a blood test. 

Approximately 1 million Americans have, or are at risk for developing, Fragile X. 

All Fragile X conditions are genetic, passed through generations (often unknowingly—as was the case with our family!) 

Fragile X can be passed on by carriers of the FMR1 gene mutation, who have no apparent signs of FX.  Hayden’s Grandma, my mother, is a carrier of fragile x. 

Females who are carriers of the Fragile X gene mutation have a 50/50 chance of passing FX on to each of their children. The gene was passed on to me but not my sister. 

Males who are carriers of the Fragile X gene will pass the gene to all of their daughters (giving them his X chromosome), but can not pass it to a son (they get his Y chromosome). In our family the male carrier was my grandfather & he passed the gene to my mom (& both of her sisters, but not her brother). 

The full mutation (over 200 repeats) causes the FMR1 gene to “turn off” & not work properly.

Approximately 1 in every 3,600 - 4,000 males have the full mutation of Fragile X.

The number is slightly less prevalent in females, with an estimated 1 in 4,000 - 6,000 having the full mutation of Fragile X.

Fragile X syndrome is the leading known cause of inherited intellectual disability.

Although Fragile X syndrome occurs in both males & females, & both can have a wide range of severity, the symptoms are generally milder in females. The reason is because they have a second X chromosome.

I am personally an example of such a case. After Hayden tested positive, I tested positive too. I am not a carrier of the gene but I do have the full mutation. I/ we never knew, because my other X chromosome compensated.

Fragile X syndrome is the number one genetic cause of autism. We know FXS is not the only cause of autism, but so far it is the only leading known cause.

Approximately 2-6 percent of children with autism are diagnosed with fragile X syndrome. And approximately one third of people with FXS, also have autism.

People with fragile X syndrome can have a variety of behaviors including, but not limited to:

o   Hyperactivity/ short attention span

o   Difficulty making eye contact

o   Anxiety

o   Impulsive/ challenging behaviors

o   Sensory processing issues

I would say that anxiety, attention deficit, & sensory processing disorder are near the top of the list for H.

However, so is his AWESOMELY delicious personality! He is an engaging, charismatic guy… he’s funny & fun to be around & gets genuinely excited to see some of his favorite people… he is a cool dressed dude, too—albeit opinionated about his outfits sometimes—but that’s fine by me! The kid cares about the way he looks & he looks good caring ;)

People with FXS generally have many strengths:

o   Excellent imitation skills

o   Strong visual memories

o   An eagerness to help others

o   Socially-motivated & friendly

o   A wonderful sense of humor

People with fragile X syndrome often have global developmental delays, including speech delays.

Some of the physical features of fragile X syndrome can be evident from birth, & some may develop in puberty. Characteristics can include large ears, long & narrow face, high palate (roof of mouth), flat feet, & hyperflexible joints to name a few. 

Females with fragile X syndrome may tend to have difficulty with math, reading maps & graphs, recognizing social cues, & they may experience social anxiety &/or depression.

While there is currently no cure for FXS, there are many areas of treatment & intervention that can improve the lives of affected individuals… & their families! Given the proper education, therapy & support, all persons with FXS can make progress. They can continue to learn & develop skills throughout their lifespan. 

As many as 1 in every 151 women, & 1 in every 468 men, are premutation carriers of the Fragile X gene.

Fragile X-associated primary ovarian insufficiency (FXPOI) is a cause of infertility, early menopause, & other ovarian problems. This occurs in approximately 22% of female carriers. 

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult onset condition (over the age of 50)-- more prevalent in males-- but can cause neurological & psychiatric symptoms in both male & female carriers. 

Hayden’s great grandfather, my maternal grandfather, had FXTAS but we did not know it at the time. My Poppy was a physician & he was a brilliant man, but there was not enough awareness at that time. The doctor’s all believed that his decline in motor function was caused by excess fluid on the brain, from natural aging. He passed away when I was about 5 months pregnant with Hayden. 

FXTAS is often initially misdiagnosed as Parkinson’s disease, Alzheimer’s or a stroke. Features may include balance problems (ataxia), tremors, memory loss, mood instability or irritability, neuropathy (numbness of extremities), & cognitive decline.

Premutation carriers may experience some medical problems more commonly than the general population. Separate from FXPOI or FXTAS, problems may include:

o   High blood pressure

o   Depression

o   Anxiety

o   Hypothyroidism

o   Chronic pain especially related to neuropathy or fibromyalgia

o   Sleep apnea

Testing for fragile X syndrome should be provided to anyone who has:

o   A family history or clinical symptoms that suggest FXS, FXTAS, or FXPOI.

o   A family member with intellectual disabilities, developmental delay, speech & language delay, autism or learning disabilities of unknown cause.

o   Expressed an interest in or requests Fragile X premutation carrier testing.

There are medications available which can help with symptoms of Fragile X.

Currently there is nothing specifically indicated for the treatment of Fragile X, however, there is a lot of exciting & promising research in the Fragile X field. Many studies are now in human trials, & the great majority of scientists & clinicians are optimistic that new drugs will prove safe & beneficial. 

There are many families living with Fragile X all over the world, & there are many resources available via The National Fragile X Foundation. The NFXF has a comprehensive website fragilex.org & staff available to take your calls at 800-688-8765. Furthermore, there is a nationwide Community Support Network (CSN) with groups all over the country.
I am the Co-Leader for the New Jersey Fragile X Community Support Group. If you ever have any questions, I can be reached at CentralNJ@FragileX.org

Click here to support H's annual fundraising page, as part of the NFXF campaign! GO TEAM NJ!
The 2015 Virtual 5k Let 'Em Know Event!

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