GREY MATTER HETEROTOPIA

GENETICS

PATTERN OF INHERITANCE

• Sporadic/de novo (acquired gene abnormality).
• Inheritance can be autosomal recessive or X-linked.

KNOWN GENES

• FLNA - associated with bilateral periventricular nodular heterotopia, this gene abnormality is found in 80% of familial periventricular nodular heterotopia, and in 20% of those with sporadic/de novo periventricular nodular heterotopia. FLNA gene abnormalities may be associated with connective tissue disease and vascular abnormalities, such as aortic root dilatation.
• ARFGEF2 - microcephaly is seen in these cases.

CHROMOSOMAL ABNORMALITIES

A number of chromosomal deletions have been associated with periventricular nodular heterotopia, including deletions of 6q27, 7q11.23, 5p15.1 and 4p15.

FAMILY HISTORY

May be present (see above).