DCX and lissencephaly type 1 due to doublecortin gene mutation: 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.