Specification of the neurobehavioral phenotype in males with fragile X syndrome.
OBJECTIVE
A controlled clinical study was designed to identify the neurobehavioral profile that is specific to males with fragile X syndrome.


METHODS
Thirty-one males with fragile X syndrome and 30 age and IQ-matched male controls were evaluated with instruments that assess multiple domains of adaptive functioning and problem behaviors. The Vineland Adaptive Behavior Scales and the Aberrant Behavior Checklist were selected for their dimensional scaling of behavioral ratings.


RESULTS
Parent and Teacher versions of the Aberrant Behavior Checklist demonstrated a profile of behaviors specific to males with fragile X syndrome characterized by significantly higher levels of hyperactivity, stereotypic movements, and unusual speech. The Vineland Adaptive Behavior Scales revealed no fragile X-specific profile of adaptive skills development.


CONCLUSIONS
The distinct pattern of aberrant behavior observed among males with fragile X emphasizes the importance of drawing subtype distinctions within the classification of individuals with mental retardation on the basis of underlying etiology. For clinical research, specifying the fragile X phenotype is a vital part in the effort to elucidate the neurodevelopmental pathways of normal behavior and psychopathology. Understanding the fragile X symptom pattern is essential for designing symptom-specific treatment interventions, as well as for research into the efficacy of interventions strategies.
Baumgardner
T L
TL
Behavioral Neurogenetics and Neuroimaging Research Center, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
Reiss
A L
AL
Freund
L S
LS
Abrams
M T
MT
D000223:Adaptation, Psychological; D000293:Adolescent; D000294:Adolescent Behavior; D016022:Case-Control Studies; D002648:Child; D002652:Child Behavior; D002653:Child Behavior Disorders / Q000235:genetics*; D002657:Child Development; D002675:Child, Preschool; D005600:Fragile X Syndrome / Q000150:complications / Q000523:psychology*; D006801:Humans; D008297:Male; D010641:Phenotype