The broad autism phenotype questionnaire: prevalence and diagnostic classification

Area of Science:

• Psychiatry and Behavioral Science
• Genetics and Genomics
• Developmental Psychology

Background:

• The Broad Autism Phenotype (BAP) represents a set of autistic traits observed in non-autistic relatives of individuals with autism.
• The Broad Autism Phenotype Questionnaire (BAPQ) is a tool used to assess these traits.

Purpose of the Study:

• To validate the three-factor structure of the BAPQ.
• To establish new normative cutoff values for BAPQ subscales.
• To estimate the prevalence of BAP in parents of children with autism (PCAs) and comparison parents (CPs).

Main Methods:

• Administered the BAPQ to a large community sample of PCAs and CPs (n=1,692).
• Conducted exploratory factor analysis and internal consistency analyses.
• Established new normative cutoff values based on population distributions.

Main Results:

• Confirmed a robust three-factor structure of the BAPQ (aloof, pragmatic language, rigidity).
• New BAPQ cutoffs demonstrated increased specificity for BAP classification.
• Estimated BAP prevalence: 14-23% in PCAs and 5-9% in CPs.
• BAP features were more likely to co-occur in PCAs.

Conclusions:

• The BAPQ is a reliable and efficient tool for identifying meaningful subgroups of parents.
• Enhanced BAPQ utility for diagnosing the Broad Autism Phenotype.
• Findings support the BAPQ's role in understanding autism heterogeneity.