The gene COL4A2 encodes a collagen alpha chain that is present in almost all basement membranes. It is coexpressed with COL4A1. As with COL4A1, pathogenetic mutation are documentet in relation to porencephaly, small-vessel disease, and stroke.
| Clinic | Method | Carrier testing |
| Turnaround | 5 days | |
| Specimen type | genomic DNA |
| Clinic | Method | Massive parallel sequencing |
| Turnaround | 25 days | |
| Specimen type | genomic DNA |
| Clinic | Method | Genomic sequencing of the entire coding region |
| Turnaround | 25 days | |
| Specimen type | genomic DNA |