Identifying Genetically Meaningful Phenotypes in Autism: A Childhood Profile of Language and Cognition in Parents

Background: Language and cognitive delays are hallmarks of autism, and also appear to be genetically meaningful phenotypes that aggregate in families. However, knowledge of the precise linguistic and cognitive features of genetic significance is seriously lacking. Prior reports of early delays among parents have necessarily relied on retrospective reports obtained in adulthood. And, while sibling studies are proving highly informative, parental phenotypes are potentially more significant genetically, as they afford the opportunity to trace patterns of lineality and employ such characteristics in molecular genetic studies where phenotypic characteristics are examined in relation to transmission of specific molecular markers.

Objectives: This study examined directly assessed, detailed developmental language and cognitive phenotypes in parents of individuals with autism in an attempt to identify childhood profiles that may index genetic liability to autism, and which may be of use in molecular genetic studies.

Methods: Using archived language and cognitive testing records, we characterized the childhood language and cognitive skills of these parents from ages 5-10 years. Records were obtained from 48 parents of children diagnosed with autism. Archival data included summary scores for both language (e.g., vocabulary, grammar, discourse) and math (numerical representation/operations, fractions, decimals, geometry, etc.).

Results:  Analyses revealed a significant split between composite language and math skill (p<0.0005). Thirty-five out of 48 parents showed composite language scores 20 points below their composite math score.

Conclusions: This fractionation in skills resembles a profile often observed in autism. Findings suggest that a dissociation in language and math/computational ability could represent a highly specific developmental cognitive-linguistic profile indexing genetic liability among parents.