Table 2.

Studies Which have Investigated Levels of Estrogen in Autism Spectrum Disorder

Estrogen and autism spectrum disorder
Authors	Sample	Study aims	Main findings
Chakrabarti et al. [2009]	Individuals (n = 349). 143 males and 206 females, mean age = 22.5 years, SD = 2.6 years).	To investigate whether genes related to sex steroids, neural growth, and social–emotional behavior are associated with autistic traits, empathy, and Asperger syndrome.	This study found a significant association of the ERβ gene with scores on the Autism Spectrum Quotient and the Empathy Quotient in individuals with ASD.
Crider et al. [2014]	Samples of postmortem middle frontal gyrus tissues from 13 individuals who had received a diagnosis of ASD and 13 controls.	To investigate estrogen receptor beta (ERβ), aromatase (CYP19A1), and ER co‐activators in the middle frontal gyrus in individuals with ASD compared to individuals without ASD.	This study is the first to provide evidence of the dysregulation of ERβ and co‐factors in the brain of individuals with ASD. Molecular alterations within the ER signalling pathway may be one factor underlying the sex difference in ASD. Gene expression was ascertained by qRT‐PCR. A 35% decrease in ERβ mRNA expression in the middle frontal gyrus of ASD subjects was found based on the gene expression analysis. Furthermore, a reduction of 38% in aromatase (CYP19A1) mRNA expression was found in the samples derived from the ASD participants.

SD, standard deviation; M, mean; ASD, autism spectrum disorders; ERβ, estrogen receptor beta; CYP19A1, aromatase.