Abstract
RATIONALE: Arachnoid cysts are relatively common intracranial space-occupying lesions; nevertheless, familial intracranial arachnoid cysts are extremely rare, with only a few cases having been reported. PATIENT CONCERNS: The proband was a 7-year-old girl who had experienced generalized tonic-clonic seizures 5 times in the 8 days prior to admission. Nine months later, her 6-year-old younger female cousin presented to us with a 3-day history of headache. DIAGNOSES: Brain magnetic resonance imaging (MRI) confirmed the diagnosis of arachnoid cyst for both of the girls. INTERVENTIONS: A cyst-peritoneal shunting and cyst fenestration were performed for the 7-year-old girl and her cousin separately. Sanger sequencing revealed a heterozygous missense mutation (c.2576C > T) in the Arginine-Glutamic Acid Dipeptide Repeats gene (RERE). OUTCOMES: The outcome was favorable and the follow-up was uneventful. LESSONS: We hypothesize that the mutation in RERE may be associated with the pathogenesis of familial intracranial arachnoid cysts.