Case report: Two sisters with light-chain cardiac amyloidosis, a mere coincidence?

Background: Light-chain amyloidosis has always been described as a sporadic disease caused by plasma cell dyscrasia. Cardiac amyloidosis refers to cardiac involvement with infiltration of amyloid fibrils in the myocardium. The degree of cardiac involvement is the greatest predictor of prognosis. To our knowledge, AL cardiac amyloidosis has only been reported once before in first-degree relatives. Case summary: In this report, we describe the unusual cases of two sisters with light-chain cardiac amyloidosis. The first patient underwent autologous stem cell transplantation and remained in remission for 10 years until the disease relapsed and she died of end-stage heart failure. The second patient was promptly started on a chemotherapy regimen but died shortly after her initial diagnosis due to rapid progression of cardiac dysfunction. Conclusion: Cardiac amyloidosis is a severe life-threatening condition which requires a multidisciplinary diagnostic and therapeutic approach. Based on this case report, a genetic cause for AL amyloidosis might be suspected or is this a purely coincidental finding? Counselling, screening, and follow-up of other family members are very challenging. As is often the case with rare diseases, many unsolved questions remain, representing important challenges for clinicians.