TTR associated leptomeningeal amyloidosis in a Sri Lankan patient

This case report aims to contribute to the expanding genotypic-phenotypic spectrum of TTR associated leptomeningeal amyloidosis.

Neuroimaging and targeted TTR Sanger sequencing were performed on a 52-year-old female presenting with cognitive and motor symptoms.

The proband, a Sri Lankan woman, presented with a gradually progressive cognitive decline, followed by a rapid deterioration in motor function and level of consciousness. She had a significant family history of an undiagnosed neurological disorder, characterized by cognitive impairment and early death occurring in the fifth decade of life. Analysis of cerebrospinal fluid (CSF) demonstrated elevated protein levels. CT scan of the brain showed extensive leptomeningeal calcifications and hydrocephalus, and gadolinium enhanced magnetic resonance imaging (MRI) demonstrated extensive leptomeningeal enhancement in the brain and spinal cord. Genetic analysis revealed c.113 A > G, p.D38G mutation in TTR, a rare mutation with characteristic clinic-radiological central nervous system features.

Leptomeningeal amyloidosis represents the least common subtype of familial transthyretin amyloidosis, which is a life-threatening condition. Among the over 150 identified mutations, few are specifically associated with central nervous system disease. The genetic spectrum and clinical phenotypes including neuroimaging findings continue to expand. It is important to maintain a high index of suspicion for leptomeningeal amyloidosis, particularly when the presentation is not acute or when there are relapsing-remitting symptoms. Consideration of family history and early genetic testing are essential to facilitate appropriate treatment and genetic counselling.