Though it is only definitively diagnosed by a genetic test,<unk>  can be suspected if the disease is known to run in the family or if someone shows symptoms. CT scanning or MRI may be useful in indicating a diagnosis. COL4A1 may be mutated in other diseases that need to be distinguished, including brain small vessel disease with hemorrhage and HANAC syndrome. CADASIL syndrome is caused by a mutation in a different gene, but may cause similar symptoms. Sporadic<unk>  is another disorder that can appear similar.
Autosomal dominant porencephaly type I
Schizencephaly
XK aprosencephaly
Holoprosencephaly
Hemimegalencephaly
Megalencephaly
Hydranencephaly
Microhydranencephaly