Autism. Most males and about one-third of females with Fragile X show some autism-like behaviors, such as flapping hands, biting themselves, repetitious actions, and walking on toes.¹⁴ About 33 percent of children with Fragile X show enough of these behaviors to receive a formal diagnosis of autism.¹⁵ However, among people diagnosed with autism first, only about 4 percent are found to have an X chromosome with the FMR1 gene mutation.

Attention Deficit Disorder (ADD)/Attention Deficit Hyperactivity Disorder (ADHD). Between 80 and 90 percent of males, and 35 to 47 percent of females with Fragile X have an attention disorder.^16,17 They are unable to focus their attention and stay with a task. They may be disorganized. Some are hyperactive and seem to be constantly in motion.

Connective Tissue Problems. Due to weak connective tissue, people with Fragile X have a higher risk of dislocating their joints and developing hernias and ear infections than those who aren’t affected by Fragile X. About half of adults with Fragile X have a heart murmur caused by mitral valve prolapse,¹⁷ which is usually not life threatening.

Seizures. About 20 percent⁶ of children with Fragile X also experience seizures. In most cases, seizures are successfully treated with medication and disappear by adolescence.

Premature Ovarian Failure (POF). POF occurs when a woman’s ovaries stop working properly and she is under the age of 40. As mentioned earlier in this booklet, about 16 to 19 percent of females who carry a premutation gene for Fragile X experience POF, some as early as age 20.^10,11 Women with a full mutation gene for Fragile X are less likely to have POF, but do tend to go through menopause earlier than women who do not carry a mutated gene.