| Prevalence | Unknown, but estimated to be substantially rarer than](/diseases/cadasil) (which has an estimated prevalence of 2-5 per 100,000) |
| Geographic distribution | The majority of confirmed cases have been reported in **Japan** and **China**, though cases have also been identified in Turkey, Pakistan, Portugal, Spain, Romania, India, and other countries |
| Signal peptide | Targets the protein for secretion |
| IGFBP domain | Insulin-like growth factor binding protein domain |
| Serine protease domain | Catalytic trypsin-like domain responsible for proteolytic activity |
| PDZ domain | Mediates protein-protein interactions and oligomerization |
| Nonsense mutations | Creating premature stop codons |
| Frameshift mutations | Resulting in truncated, non-functional protein |
| Splice-site mutations | Disrupting mRNA processing |
| Heterozygous carriers | Historically considered asymptomatic, but now recognized to develop cerebral small vessel disease in some cases, typically with later onset (50s-60s) and without alopecia or spondylosis |
| Substrate cleavage | HTRA1 degrades TGF-beta propeptides (latency-associated peptide), mature TGF-beta ligands, and downstream effectors |
| Extracellular matrix regulation | HTRA1 cleaves fibronectin, vitronectin, decorin, fibromodulin, and other extracellular matrix (ECM) proteins, maintaining normal matrix turnover |
| Databases | OMIMOrphanetClinicalTrialsPubMed |