Recurrent subarachnoid hemorrhage associated with a new transthyretin variant (Gly53Glu)

CNS involvement is rare in systemic amyloidoses due to transthyretin (TTR) mutation and manifests as a combination of dementia, seizures, and myelopat hy. The authors report two French siblings who experienced recurrent subara chnoid hemorrhages as the main clinical feature. Brain specimens showed tha t the leptomeningeal vessels walls were thickened by amyloid deposits, and sequencing of the TTR exons showed a heterozygous single base-pair transiti on from G to A (codon 53), resulting in a glycine for glutamic acid substit ution (G53E).