Fragile X Syndrome

Fragile X Syndrome is an inherited genetic condition associated with mental retardation. 

The spectrum of Fragile X Syndrome ranges from normal development to developmental delay, learning disabilities, mild to severe intellectual disability, autistic-like behavior, and attention problems.  Fragile X is a "sex-linked" abnormality identified by a break or weakness in the long arm of the X chromosome.  The syndrome was linked to a gene, FMR-1, in May of 1991; it appears this gene is responsible for the disease characteristics.

Because Fragile X is a "sex-linked" abnormality of the X chromosome, females tend to be carriers while males are at risk for acquiring the syndrome.  Fragile X is not transmitted from father to son.   Estimates suggest about 1 in 4,000 males are affected and that about 1 in 1,000 females carry the gene.  Although females are carriers, a small percentage of females may demonstrate signs of the syndrome. 

Classic physical, developmental, and behavioral characteristics associated with the syndrome:

bulletPhysical Characteristics:

bulletElongated face with prominent jaw

bulletProminent, large ears

bulletHigh, arched palate

bulletLarge testicles, usually following puberty

bulletRecurrent ear infections

bulletConnective tissue abnormalities, loose joints in fingers, flat feet, congenital hip dislocation, and scoliosis

bulletPoor muscle tone

bulletMitral valve prolapse

bulletSeizure disorders

bulletEye problems, including strabismus

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Developmental Characteristics

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Intellectual disability

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Learning disabilities

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Fine and gross motor delays

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Coordination difficulties

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Speech and language delays

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Speech problems are often one of the earliest presenting signs, characterized by speech of a narrative style with perseveration (repeating a word or phrase over and over) and echolalia (echoing or mimicking a word or phrase without apparent understanding).  The child with Fragile X may skip from topic to topic or subject to subject in conversation.

bulletBehavioral Characteristics

bulletAttention deficit disorders

bullet Autistic-like behaviors

bullethand-flapping

bulletself-biting

bulletgaze aversion

bulletstereotypical preoccupation with objects

bulletDifficulty adjusting to change

bulletSocial anxiety

bulletShyness (this often makes the child particularly engaging)

bulletHyperarousal

bulletSensory defensiveness (aversion to loud noises, touch, strong smells, and/or eye contact)

bulletMood instability with aggression and/or depression

A multidisciplinary approach is often the most successful management strategy involving parents, genetic counselors, pediatricians, speech pathologists, special educators, physical and occupational therapists, and psychologists.

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Links

The National Fragile X Foundation

Information Sheet Home

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Information on this sheet contains only suggested guidelines. Each person must be considered individually, and in many cases, a physician's written consent should be obtained. Developed by Texas Woman's University Graduate Adapted Physical Education Program in cooperation with Denton ISD (French, 1997).