Signs & Symptoms

Fragile X Syndrome

In Males

Behavioral characteristics can include ADD, ADHD, autism and autistic behaviors, social anxiety, hand-biting and/or flapping, poor eye contact, sensory disorders, and increased risk for aggression.

Intellectual disabilities in FXS include a range from moderate learning disabilities to more severe intellectual disabilities. The majority of males with Fragile X syndrome demonstrate significant intellectual disability.

Physical features may include large ears, long face, soft skin, and large testicles (called “macroorchidism”) in post-pubertal males. Connective tissue problems may include ear infections, flat feet, high arched palate, double-jointed fingers, and hyper-flexible joints. No one individual will have all the features of FXS, and some features, such as a long face and macroorchidism, are more common after puberty.

Disposition: They are also very social and friendly, have excellent imitation skills, have a strong visual memory/long term memory, like to help others, are nice, thoughtful people and have a wonderful sense of humor.

In Females

Behavioral characteristics seen in males can also be seen in females, though females often have milder intellectual disability and a milder presentation of the syndrome’s behavioral and physical features.

Intellectual disabilities: About one-third of females with FXS have a significant intellectual disability. Others may have moderate or mild learning disabilities, emotional/mental health issues, general anxiety, and/or social anxiety.

A small percentage of females who have the full mutation of the FMR1 gene that causes FXS will have no apparent signs of the condition—intellectual, behavioral, or physical. These females are often identified only after another family member has been diagnosed.

Be a part of the solution.

Learn more about the INTERNATIONAL FRAGILE X PREMUTATION REGISTRY and join individuals with the premutation and their families to help advance — and encourage — deeper understanding and research into the premutation condition.

International Fragile X Premutation Registry
International Fragile X Premutation Registry

Be a part of the solution.

Learn more about the International Fragile X Premutation Registry and join individuals with the premutation and their families to help advance — and encourage — deeper understanding and research into the premutation condition.


Fragile X-Associated Primary Ovarian Insufficiency

Common symptoms of FXPOI include absent or irregular cycles, “sub-fertility” or infertility, hot flashes, and premature ovarian failure (POF), which is the complete cessation of menstrual periods before the age of 40. In the wider range of FXPOI symptoms, premature ovarian failure is at the more severe end of the spectrum.

FMR1 premutation carriers can have normal ovarian function, but can still go through early menopause, which is menopause occurring between 40 and 45 years of age (menopause normally occurs between 45 and 55 years old).

Even though women with FXPOI may develop symptoms similar to those of menopause, such as hot flashes and vaginal dryness, FXPOI differs from menopause in some important ways:

Women with FXPOI Women who have completed menopause
Can still get pregnant in some cases because their ovaries may occasionally function to release viable eggs. Cannot get pregnant because their ovaries no longer release eggs.
Can experience a return of menstrual periods. Cannot have menstrual periods again.

Learn more about FXPOI »

Fragile X–Associated Tremor/Ataxia Syndrome

The symptoms of FXTAS are divided into minor and major clinical and MRI findings. The diagnosis is then categorized into definite, probable, or possible FXTAS. The criteria were developed primarily as a reflection of the presenting symptoms in men. As we learn more about FXTAS in females, the diagnostic criteria may become different for females, since they usually have milder symptoms. Both the type and severity of FXTAS symptoms vary among individuals. Some will have multiple symptoms that progress rapidly, others few symptoms that remain mild over many years.

There are also comorbid symptoms of FXTAS, which means they often occur in individuals with FXTAS but aren’t used to confirm the diagnosis (just as a sore throat is a symptom of strep throat, but cultures, fever, etc., are also used to make the diagnosis).

With FXTAS being a relatively new disorder, there may not appear to be as many services and professionals available as there is for other medical conditions. However, a number of support services and informational materials may be of value to those impacted by FXTAS, some of which address symptoms common to other medical conditions such as Parkinson’s.

Major FXTAS Symptoms

  1. Intention tremor: A tremor of the hand when using utensils or writing instruments, reaching for or pouring something. The tremor is not as apparent at rest.
  2. Gait ataxias: Balance problems that may include falling, needing support when walking or going up/down stairs, trouble stepping on/off curbs, generalized instability, or display of a wide-based gait.
  3. MRI findings strongly associated with (but not unique to) FXTAS. These findings include white matter lesions involving middle cerebellar peduncles (MCP) signs.
  4. Neuropathology findings called “FXTAS inclusions” within brain cells.

Minor FXTAS Symptoms

  1. Parkinsonism (resting tremors).
  2. Short-term memory problems. This can be difficult to determine since it is natural for short-term memory to deteriorate as we age. However, in FXTAS it can change more rapidly than normal or may be more dramatic, such as forgetting what one ate, said, or did shortly after the event.
  3. Problems with executive function and decision-making. Executive function includes the ability to initiate and complete an activity, to adapt and change behavior as needed, and to anticipate and plan for new tasks and situations. Executive function allows us to anticipate outcomes, solve problems, and generalize from one situation to the next.
  4. MRI findings that are more general than those listed above, referred to as “lesions of cerebral white matter.” And other MRI findings indicating “moderate to severe generalized brain atrophy.”

Other FXTAS Symptoms

These are not considered to be official diagnostic criteria.

  • Neuropathy or numbness/tingling of the extremities.
  • Mood instability, irritability, explosive outbursts, personality changes.
  • Cognitive decline, including loss of skills such as math, reading, etc.
  • Autonomic functioning problems such as impotence, loss of bladder or bowel functions.
  • High blood pressure, thyroid disorders, fibromyalgia (more common in females and very common in the general population).

Learn more about FXTAS »