The second study compared whole brain, amygdala, and hippocampus volumes of subjects identified from the Denver birth cohort study in 10 47,XXX females (mean age 29.1, SD 2.1 years) with 10 healthy controls individually matched on age (mean age 28.5 years, SD 3.21 years) [Patwardhan et al., 2002]. IQ in the 47,XXX group had been measured when the subjects were children and was 81.73 (SD 15.84) [Bender et al., 1993a]. MRI results showed that total brain volume was significantly smaller in the 47,XXX group; although there was a trend toward smaller volume of the amygdala, it did not reach significance, and hippocampal volume was not different.
