Among the cases that were successfully typed, AL amyloidosis was found in two (one kappa and one lambda light chain, and monoclonal gammopathy was diagnosed later in both patients); the third case was positive for transthyretin with traces of kappa light chain and serum amyloid protein, and a subsequent endomyocardial biopsy confirmed the presence of amyloid. This evidence concerns the gene TTR and amyloidosis.