Affiliations: Department of Pediatrics, Rush University Medical
Center, Chicago, IL, USA | Department of Neurological Sciences, Rush University
Medical Center, Chicago, IL, USA | Department of Biochemistry, Rush University Medical
Center, Chicago, IL, USA | Department of Medicine, Rush University Medical
Center, Chicago, IL, USA
Note: [] Correspondence: Dr. Deborah A. Hall, Department of Neurological
Sciences, Rush University, 1725 West Harrison St, Suite 755, Chicago, IL 60611,
USA. Tel.: +1 312 563 2900; Fax: +1 312 2684; E-mail:
Deborah_A_Hall@rush.edu
Abstract: The purpose of this study was to quantify the type and frequency of
stereotypies in fragile X syndrome and to determine the relationship of
observed stereotypies with gender, level of cognitive function, and
parent-reported scores for repetitive behaviors. Subjects with fragile X
syndrome were videotaped during the administration of a standardized
conversation task, a standardized narrative task, and sitting alone. Two
individuals rated the stereotypies on the videotapes (10 min each) using the
stereotyped behavior scale. Intelligence quotient scores were collected and
parents/guardians completed the Vineland adaptive behavior scale and the
aberrant behavior checklist – community edition. Thirty-eight subjects
were tested (mean age 17.1 ± 7.1 yr). The mean total of stereotypies was
11 ± 11.7 movements in 10 min and the mean stereotyped behavior scale
score was 5.8 ± 5.5. The most common type of movement was rubbing
him/herself, followed by body movement and repetitive movement. There were
correlations between the stereotyped behavior scale score and intelligence
quotient (P=0.0006), the aberrant behavior checklist total score (P=0.01), and
the stereotypy subscore (P=0.0007). Stereotypies are common in fragile X
syndrome and more frequent in individuals with lower intelligence quotients and
more severe behavior. The stereotyped behavior scale measure correlated with
parent completed checklists, but showed poor to moderate reliability for
measurement of stereotypies by a single rater and test retest in fragile X
syndrome.
Keywords: Fragile X syndrome, stereotypies, FMR1, autistic disorder
