A Rare Unusually Aggressive Form of Hereditary Transthyretin Amyloidosis.

BACKGROUND

Hereditary transthyretin amyloidosis (ATTRv) is more typically associated with earlier onset and neurological symptoms compared with wild-type ATTR, although a very early, very symptomatic disease presentation is rare.

CASE SUMMARY: A 21-year-old male with gastrointestinal distress and neuropathy underwent cardiac evaluation after gastrointestinal biopsies identified ATTR. Family history was notable for amyloidosis and premature deaths. Examination showed neurological deficits without clinical heart failure, and echocardiogram showed concentric left ventricular remodeling. TTR gene sequencing identified a rare pathogenic variant, p.Phe84Ser. Magnetic resonance imaging demonstrated diffuse leptomeningeal enhancement of the brain and spine. Treatment with vutrisiran and tafamidis was initiated.

DISCUSSION: The p.Phe84Ser variant is strongly associated with central nervous system and gastrointestinal involvement. This patient had an early phenotypic presentation with leptomeningeal amyloidosis, which is exceedingly rare.

TAKE-HOME MESSAGE: Understanding the phenotype associated with this ATTRv genotype, along with the patient's family history, guided targeted and timely evaluation and treatment.