LISSENCEPHALY

GENETICS

PATTERN OF INHERITANCE

The pattern of inheritance depends on the gene abnormality. LIS1 and TUBA1A occur as acquired gene abnormalities. DCX can be inherited in an X-linked pattern. Rare forms of lissencephaly may have autosomal recessive inheritance.

KNOWN GENES

Classical lissencephaly:

• LIS1 - accounts for half of all cases of classical lissencephaly, with a posterior to anterior gradient of lissencephaly seen, this gene abnormality may occur in isolation or in association with Miller Dieker syndrome
• DCX - accounts for 10% of all cases of classical lissencephaly, with an anterior to posterior gradient of lissencephaly seen, and a male predominance (females have subcortical band heterotopia)
• ARX - lissencephaly with agenesis of the corpus callosum and with abnormal genitalia in males
• RELN - lissencephaly with cerebellar hypoplasia
• TUBA1A - lissencephaly with a posterior to anterior gradient, may have associated cerebellar hypoplasia
• Other genes: DYNC1H1, KIF2A, KIF5C, TUBG1

Cobblestone lissencephaly: POMT1, POMT2, LARGE, FKTN and FKRP

FAMILY HISTORY

May be present (see above).