Elevated androgen, brain development and language/learning disabilities in children with congenital adrenal hyperplasia

Individuals with congenital adrenal hyperplasia (CAH) provide a test population for the theory that elevated testosterone levels alter prenatal brain development and increase the risk of learning disabilities. Eleven subjects with CAH, five of their non-CAH siblings and 16 matched control subjects participated in two studies. The first study documented hand preference, verbal skills and non-verbal skills. A higher prevalence of language/learning disability was found in both the CAH subjects and their families than in the control subjects. The second study examined the prevalence of atypical perisylvian asymmetries on MRI scans. These revealed an atypical pattern of asymmetry (R = L or R > L) in the majority of the subjects with CAH and in all of their siblings. One subject with CAH also showed evidence of a neuromigratory disturbance in the posterior left hemisphere. Of the control subjects, only one showed an atypical pattern of asymmetry and none showed evidence of a neuromigratory disorder. The findings indicate that an elevated familial rate for language-based learning disabilities and altered brain asymmetries co-occur in families with the gene for CAH.