COL4A1 encodes the alpha-1 chain of type IV collagen, a critical structural component of basement membranes across multiple tissues 1. Two proα1(IV) chains encoded by COL4A1 form trimers with a proα2(IV) chain to constitute major basement membrane components 1. The protein possesses anti-angiogenic activity through its C-terminal NC1 domain (arresten), which specifically inhibits endothelial cell proliferation, migration, and tube formation. COL4A1 is upregulated during wound reepithelialization and plays roles in extracellular matrix organization and vascular morphogenesis 2. In heart failure with preserved ejection fraction, COL4A1 expression is elevated in activated cardiac fibroblasts, contributing to perivascular fibrosis 3. Additionally, COL4A1 expression increases during epithelial-to-mesenchymal transition in renal tubular cells 4. Pathogenic COL4A1 variants cause autosomal dominant COL4A1/A2-related disorders, characterized by multisystem manifestations including cerebrovascular disease, seizures, porencephaly, ophthalmologic abnormalities, and renal dysfunction 56. Stroke and epilepsy represent the most frequent severe neurological complications, with childhood-onset focal seizures often resistant to antiepileptic drugs 7. The high phenotypic variability and reduced penetrance complicate genetic counseling, necessitating multidisciplinary management including neurological, ophthalmological, cardiovascular, and renal monitoring 5.