Sex Differences in Autistic Profiles in Preschool Children with Autism Spectrum Disorders.

Background: Epidemiological studies have consistently shown that autism spectrum disorders (ASD) affect more males than females. Studies have reported that females with ASD have a different behavioral phenotype from that of their male counterparts. Females with ASD have a lower frequency of comorbid challenging behaviors and fewer abnormal special interests and concurrent socio-communication symptoms than males with ASD. They also have less externalizing and social problems and present fewer socio-communication symptoms. It has been suggested that there is a relative failure to diagnose females with ASD because of differences in the clinical presentation of ASD. The delay in (or complete absence of) diagnosis results in a failure of necessary support for females with ASD, which could create serious identity issues and higher levels of internalizing symptoms (i.e., withdrawal, somatic complaints, anxiety, and depression). Early identification and diagnosis of ASD in females are important, as they lead to earlier treatment, which is associated with improved developmental outcomes.

Objectives: The purpose of this study is to examine the sex differences in young subjects with ASD.

Methods: We examined sex differences in ASD among children under 6 years, using the Kyoto Scale of Psychological Development and the Childhood Autism Rating Scale-Tokyo Version (CARS-TV). Seventeen females with ASD were compared with 100 similarly diagnosed males.

Results: Although females and males with ASD showed similar cognitive profiles on the Kyoto Scale of Psychological Development, females with ASD demonstrated a different symptom profile from males with ASD on the CARS-TV. Females with ASD had a significantly higher “Taste, Smell, and Touch Response and Use” score than males with ASD.

 Conclusions: The notable finding in this study was found in the CARS-TV, in which female subjects scored significantly higher than male subjects on “Taste, Smell, and Touch Response.” This result may assist in planning early diagnosis as well as intervention methods for females with HFASDs who might have been under-recognized. Some researchers consider sensory symptoms to be a component of core ASD deficits. We propose that “Taste, Smell, and Touch Response and Use” may be useful for the early identification of ASD in females. The sex differences in “Taste, Smell, and Touch Response and Use” in our study, if replicated in other samples, could lead to the development of useful diagnostic tools, increasing service and therapeutic efficacy for female children with HFASDs. The presence of the unique autistic features identified in this sample of females should be replicated with a larger sample, and future research should clarify possible behavioral, neurological, and genetic links to these sex differences.