Case Report: Hereditary ATTR-CA presenting with recurrent severe abdominal cramps: a diagnostic challenge.

Background: Hereditary transthyretin cardiac amyloidosis (ATTR-CA) is a rare autosomal dominant systemic disorder characterized by amyloid deposition in the peripheral nerves, myocardium, kidneys, and gastrointestinal tract. The clinical manifestations of ATTR-CA are nonspecific, resulting in high rates of misdiagnosis and underdiagnosis. Case presentation: We report the case of a 58-year-old woman who presented with recurrent severe abdominal pain and echocardiographic evidence of ventricular hypertrophy. Initial cardiac magnetic resonance imaging at an outside institution suggested left ventricular non-compaction (LVNC). Prior to receiving the correct diagnosis, she was incorrectly diagnosed with chronic cholecystitis, somatic symptom disorder, or LVNC at multiple institutions. A multidisciplinary team evaluation integrating cardiac imaging, technetium-99m phosphate scintigraphy, and genetic testing confirmed the diagnosis of ATTR-CA associated with the Ser23Asn (TTR c.128G>A p.Ser43Asn) variant. She was treated with tafamidis but died suddenly only two months after diagnosis. This case illustrates the multisystem involvement of ATTR-CA, in which atypical presentations frequently result in diagnostic delays. It represents a rarely reported instance of ATTR-CA presenting primarily with severe recurrent abdominal pain. Conclusion: In patients with ventricular hypertrophy, ATTR-CA may manifest with atypical symptoms such as severe, recurrent abdominal pain, which can result from autonomic neuropathy or gastrointestinal amyloid deposition. When the clinical diagnosis remains uncertain, multidisciplinary team consultation is essential to synthesize all available findings.