A novel CCM1/KRIT1 heterozygous deletion mutation (c.1919delT) in a Chinese family with familial cerebral cavernous malformation.

BACKGROUND: Cerebral cavernous malformation (CCM) is a relatively rare congenital vascular anomaly in the central venous system. Its inherited form, familial cerebral cavernous malformation (FCCM), is an autosomal-dominant disease with incomplete penetrance. The pathogenic genes of FCCM have been mapped into three loci: CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10. Till now, the genetic basis of FCCM in the Chinese population has yet to be well understood. Herein, we investigated the genetic mutation in a Chinese family with FCCM.

CASE REPORT: The proband is a 29-year-old female presenting with a 1-month history of headache. Brain magnetic resonance imaging (MRI) revealed multiple intracranial lesions, the largest one showing a popcorn-like appearance. After a 4-year conservative observation, there was no significant clinical or radiological progression. Family investigation found five of her relatives had multiple CCM lesions. DNA sequencing analysis in the proband disclosed a novel heterozygous deletion mutation (c.1919delT; p.Phe640SerfsX21) in exon 17 of the CCM1/KRIT1 gene. This mutation leads to a frameshift and is predicted to cause a premature termination codon to generate a truncated Krev interaction trapped-1 (Krit1) protein of 659 amino acids. The mutation segregated with the disease in the family.

CONCLUSION: The current study identified a novel CCM1/KRIT1 heterozygous deletion mutation (c.1919delT) associated with FCCM. Our findings expand the CCM gene mutation profiles in the Chinese population, which will be beneficial for genetic counseling.