Prevalence of the fragile X anomaly amongst autistic twins and singletons.

J Child Psychol Psychiatry 1993 Jul;34(5):673-88

MRC Child Psychiatry Unit, Institute of Psychiatry, London, U.K.

Early screening studies of autistic individuals suggested that up to one-quarter of cases were associated with the Fragile X anomaly. Recent studies find that the usual behavioural phenotype of the Fragile X anomaly is distinct from autism as usually defined, and that a variety of methodological factors contribute to the variability of the prevalence estimates. We report the prevalence of the Fragile X anomaly, using strict cytogenetic criteria, in a large sample of autistic individuals whose diagnosis was confirmed using a standardised diagnostic instrument. The anomaly was detected in 1.6% of tested autistic individuals from a combined sample of: autistic twins; clinic attenders; and, individuals from families multiplex for autism or related cognitive phenotypes. The anomaly was not detected in greater than 2.5% of any of the constituent samples and accounted for only a small proportion of the genetic influences amongst concordant twins and multiplex families. The anomaly was detected in 5% of the 40 tested autistic females, confirming reports that the prevalence of the anomaly is similar amongst autistic individuals of both sexes.

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http://dx.doi.org/10.1111/j.1469-7610.1993.tb01064.xDOI Listing
July 1993

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References

(Supplied by CrossRef)

August G. et al.
British Journal of Psychiatry 1981

Bailey A. et al.
Psychiatric Genetics 1991

Bartak L. et al.
British Journal of Psychiatry 1975

Blomquist H. et al.
Clinical Genetics 1985

Bolton P. et al.
International Review of Psychiatry 1990

Bolton P. et al.
Psychiatric Genetics 1991

Bolton P. et al.
Psychiatric Genetics

Cohen I. et al.
American Journal on Mentall Retardation 1988

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