<unk>  is caused by mutations in a gene called COL4A1, located at 13q34 (band 34 on the long arm of chromosome 13). These mutations are inherited in an<unk><unk>  pattern. COL4A1 codes for a form of collagen, collagen<unk>  IV, which is an important element in the construction of the vascular basement membrane. When collagen<unk>  IV is not functioning properly, the basement membrane is weak and the blood vessel is susceptible to damage from trauma or may burst. Damaged blood vessels in the skull or brain cause cysts to form.
Autosomal dominant porencephaly type I
Schizencephaly
XK aprosencephaly
Holoprosencephaly
Hemimegalencephaly
Megalencephaly
Hydranencephaly
Microhydranencephaly