Conversational analyses of males with fragile X, Down syndrome, and autism: comparison of the emergence of deviant language.

Deviant, repetitive language of 33 males (9 with Down syndrome, 12 with fragile X (fra[X]) syndrome, and 12 with autism) was analyzed within three conversational contexts: direct responses, initiation of new material, and topic maintenance. Results indicated that males with fra(X) manifest deviant, repetitive language that is distinct from males with either Down syndrome or autism. Thus, the deviant repetitive language of males with fra(X) cannot be accounted for by either their level of adaptive functioning or autistic-like behaviors per se. Possible explanations for this etiologically specific language deviance were discussed.

Social gaze, social avoidance, and repetitive behavior in fragile X males: a controlled study.

Preference for social gaze as well as the percentage occurrence of social gaze, nonverbal social avoidance, and nonverbal repetitive behaviors were examined in autistic and nonautistic prepubertal males with the fragile X syndrome (fra[X]) during social interaction with a parent or stranger. Comparison groups were nonhandicapped, Down syndrome, atypical pervasive developmental disorder, and autistic males. The subjects with fra(X) and the nonhandicapped and Down syndrome control subjects discriminated parent from stranger as evidenced by their avoidance behavior. The overall percentage of avoidance was higher, however, for both parent and stranger, among the males with fra(X). Autistic and atypical groups without fra(X) failed to discriminate parent from stranger in their avoidance behavior. Possible explanations for these group differences in terms of language level or degree of language demand were ruled out. Implications for research concerning the relations among fra(X), autism, and mental retardation were discussed.

Fragile X and autism: a multicenter survey.

We screened 183 autistic males for the fra(X) and found 24 (13.1%) to be positive. Adding the subjects of this study to those of 11 other surveys, of which 6 were positive and 5 were negative, a total of 614 autistic males have been screened. Overall 47 (7.7%) were positive. Based on this estimate and the prevalence of autism and fra(X), we estimate that 12.3% of fra(X) males are autistic. We have found that 17.3% of our fra(X) males were autistic and overall a 21.2% frequency has been reported, these higher figures are most likely due to biases in age and ascertainment. With an overall 7.7% frequency of fra(X) among autistic males and an estimated 12.3% of autism among fra(X) males, we conclude there is likely to be a significant association of fra(X) with autism. Because fra(X) appears to be the single most common cause of the condition, chromosomal testing is recommended for any autistic person with undiagnosed etiology.

High dose folic acid treatment of fragile (X) males.

We conducted an experimental trial of high-dose folic acid given to five males, ages 8 to 26 years, with the fra(X) syndrome. In this double blind study, each subject received 250 mg per day of folic acid for 3 months, followed by placebo for 3 months, and folic acid again for an additional three months. Based on IQ tests, behavior ratings, the Autistic Descriptors Checklist, and parental ratings, there was little evidence to suggest any positive effects seen during the administration of high-dose folic acid. Therefore, this study has provided little support for a hypothesis of benefit of high-dose folic acid in the treatment of the fra(X) syndrome.