The prognosis for girls with Aicardi Syndrome varies according to the severity of their symptoms.
Aicardi syndrome only affects females, and in very rare cases, males with Klinefelter syndrome (XXY). It is theorized to result from a defect on an x-chromosome, though until the gene is found, this cannot be confirmed. There is only one case of siblings with the syndrome reported upon in the literature, suggesting that almost all cases are new mutations and other family members do not carry the defective gene.