CCM2_HHD is a folded-helical region of a family of vertebral proteins, mutations in which cause cerebral cavernous malformations (CCMs). These malformations are congenital vascular anomalies of the central nervous system that can result in haemorrhagic stroke, seizures, recurrent headaches, and focal neurologic deficits. This domain is structurally homologous to the N-terminal domain of harmonin, so it is named the CCM2 harmonin-homology domain or CCM2_HHD. This protein is often called Malcavernin.
Jiyao W et al.(2023). "The conserved domain database in 2023.",