Comparison groups in autism family research: Down syndrome, fragile X syndrome, and schizophrenia.
Pick fragile X or schizophrenia comparison groups, not just Down syndrome, to see clearer autism family patterns.
01Research in Context
What this study did
Seltzer et al. (2004) wrote a guide for researchers.
They said: stop using only Down syndrome as a comparison group when you study autism families.
Add fragile X or schizophrenia groups and use stats to pull out clearer differences.
What they found
The paper has no new data.
It is a roadmap.
It tells scientists which extra groups give sharper pictures of autism family life.
How this fits with other research
Thurman et al. (2015) followed the advice. They tracked autism traits in boys with fragile X across time and saw paths unlike nonsyndromic ASD.
Stancliffe et al. (2007) also used the FXS-DS pair. They found boys with DS had lower receptive language than boys with FXS-only, proving the extra contrast works.
Granich et al. (2016) went bigger. They added Cornelia de Lange, Angelman and Rubinstein-Taybi to the mix and showed caregivers rate sociability lowest in fragile X, Cornelia de Lange and ASD, not Down syndrome.
Kealhofer et al. (2025) backs the schizophrenia angle. Shared gene networks link ASD and schizophrenia, so comparing the two disorders makes biological sense.
Why it matters
If you assess a child with ASD, choose tests with fragile X or schizophrenia norms, not just Down syndrome. You will spot unique strengths and needs faster. When writing reports, say why you picked each reference group. It sharpens your recommendations and keeps you in line with the newest evidence.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Use fragile X norms when you score social or language tests for a child with ASD.
02At a glance
03Original abstract
This paper examines methodological challenges inherent in conducting research on families of children with autism and in comparing these families with others who are coping with different types of disabilities or who have nondisabled children. Although most comparative research has contrasted families whose child has autism with those whose child has Down syndrome, the range of comparison groups can be expanded to offer additional points of contrast and control. We discuss both matching and statistical control procedures and point to next steps in this line of comparative autism family research.
Journal of autism and developmental disorders, 2004 · doi:10.1023/b:jadd.0000018073.92982.64