This is one of 5 complement factor H-related genes that occur in tandem with CFH. All these genes though less transcribed share some structural domains and functional properties with complement factor H. Some mutations and polymorphisms have been associated with atypical HUS and age-related macula degeneration. No mutations have been identified in the CFHR4 gene yet.
| 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 |
| Clinic | Method | Multiplex Ligation-Dependent Probe Amplification |
| Turnaround | 20 days | |
| Specimen type | genomic DNA |