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Articles by C Steer
Total Records ( 2 ) for C Steer
  B St. Pourcain , K Wang , J. T Glessner , J Golding , C Steer , S. M Ring , D. H Skuse , S. F. A Grant , H Hakonarson and G. Davey Smith
  Objective:

Recent genome-wide analysis identified a genetic variant on 5p14.1 (rs4307059), which is associated with risk for autism spectrum disorder. This study investigated whether rs4307059 also operates as a quantitative trait locus underlying a broader autism phenotype in the general population, focusing specifically on the social communication aspect of the spectrum.

Method:

Study participants were 7,313 children from the Avon Longitudinal Study of Parents and Children. Single-trait and joint-trait genotype associations were investigated for 29 measures related to language and communication, verbal intelligence, social interaction, and behavioral adjustment, assessed between ages 3 and 12 years. Analyses were performed in one-sided or directed mode and adjusted for multiple testing, trait interrelatedness, and random genotype dropout.

Results:

Single phenotype analyses showed that an increased load of rs4307059 risk allele is associated with stereotyped conversation and lower pragmatic communication skills, as measured by the Children's Communication Checklist (at a mean age of 9.7 years). In addition a trend toward a higher frequency of identification of special educational needs (at a mean age of 11.8 years) was observed. Variation at rs4307059 was also associated with the phenotypic profile of studied traits. This joint signal was fully explained neither by single-trait associations nor by overall behavioral adjustment problems but suggested a combined effect, which manifested through multiple sub-threshold social, communicative, and cognitive impairments.

Conclusions:

Our results suggest that common variation at 5p14.1 is associated with social communication spectrum phenotypes in the general population and support the role of rs4307059 as a quantitative trait locus for autism spectrum disorder.

  D Wolke , A Waylen , M Samara , C Steer , R Goodman , T Ford and K. Lamberts
 

Background

Participant drop-out occurs in all longitudinal studies, and if systematic, may lead to selection biases and erroneous conclusions being drawn from a study.

Aims

We investigated whether drop out in the Avon Longitudinal Study of Parents And Children (ALSPAC) was systematic or random, and if systematic, whether it had an impact on the prediction of disruptive behaviour disorders.

Method

Teacher reports of disruptive behaviour among currently participating, previously participating and never participating children aged 8 years in the ALSPAC longitudinal study were collected. Data on family factors were obtained in pregnancy. Simulations were conducted to explain the impact of selective drop-out on the strength of prediction.

Results

Drop out from the ALSPAC cohort was systematic and children who dropped out were more likely to suffer from disruptive behaviour disorder. Systematic participant drop-out according to the family variables, however, did not alter the association between family factors obtained in pregnancy and disruptive behaviour disorder at 8 years of age.

Conclusions

Cohort studies are prone to selective drop-out and are likely to underestimate the prevalence of psychiatric disorder. This empirical study and the simulations confirm that the validity of regression models is only marginally affected despite range restrictions after selective drop-out.

 
 
 
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