DCX and ARX are genes located on the X chromosome, and their mutation in males (in a hemizygous state) causes lissencephaly.6 Females having this gene mutation present with a milder form of lissencephaly.7 Ambiguous genitalia and absent corpus callosum are associated with X-linked lissencephaly. The gene discussed is DCX; the disease is lissencephaly spectrum disorders.