Cerebral cavernous malformations (CCMs) are relatively rare intracranial vascular anomaly. They are associated with various clinical manifestations, including cerebral vascular accidents (CVAs), seizures, headaches, or they can remain asymptomatic. CCM can be broadly categorized into sporadic and familial forms (FCCM), which is defined by the occurrence of CCM in multiple family members, often presenting with multiple lesions. FCCM is an autosomal dominant disorder caused by mutations in three genes: KRIT1 (krev interaction trapped 1 protein)/CCM1, CCM2, and PDCD10. Current research data suggest that KRIT1 mutations may be responsible for more than 40% of cases of FCCM.

We presented a case of a Korean family affected by FCCM, we comprehensively analyzed clinical data, imaging findings, and genetic testing results.

The proband is a 34-year-old Korean woman with a history of sporadic headaches. She presented with an acute onset of aphasia and subtle right facial asymmetry. A head CT scan revealed a 1.2 cm left posterior temporal/parietal hemorrhage. Brain MRI further showed a 2.0 cm focal parenchymal hematoma in the left temporal lobe, accompanied by numerous small old microhemorrhages scattered throughout her brain. These MRI findings strongly suggested the presence of CCMs. Genetic testing revealed the identification of a novel heterozygous frameshift mutation, c.1141dup, resulting in p.(Asp381Glyfs*2), within the KRIT1 gene.

The proband's father had a history of stroke in his 30s and later suffered an intracranial hemorrhage at the age of 65. His brain imaging displayed numerous CCMs. Additionally, the proband's father, sister, parental uncle, and the uncle's two children all tested positive for the same KRIT1 gene mutation (Figure 1).