The hereditary systemic amyloidoses are a group of diseases caused by mutations in several structural proteins. The most common is transthyretin (TTR) amyloidosis, which is characterized mainly by peripheral neuropathy but also associated, in many cases, with restrictive cardiomyopathy. Systemic amyloidoses associated with mutations in fibrinogen Aα-chain, lysozyme, apolipoprotein A-I, and apolipoprotein A-II, are mainly associated with renal amyloidosis but may also affect other organ systems. As with all types of amyloidosis, organ dysfunction is caused by deposition of protein fibrils (∼10 nm in diameter) which, as they accumulate, displace normal tissue structures. As amyloid deposition progresses organ failure ensues often leading to death within a 10- to 15-year period. Since clinical diagnosis is often delayed until the disease is relatively advanced, death within 5 to 10 years after tissue diagnosis is not uncommon.