A descriptive study of transthyretin amyloidosis in a tertiary hospital without a referral unit.

BACKGROUND AND OBJECTIVE: Transthyretin amyloidosis (ATTR) is a rare disease that is part of systemic amyloidosis and is life-threatening. It can affect all organs and systems, the most frequent being neurological and cardiac involvement. This study aims to detect possible ATTR cases and carry out a descriptive study of them. MATERIAL AND METHODS: Descriptive single-centre study carried out in a tertiary hospital, which included patients with suspected ATTR between September 2016 and January 2020. RESULTS: A total of 190 suspected ATTR patients were detected. The study includes 100 of these patients, as well as 10 relatives of patients in whom ATTR was detected in its genetic variant (ATTRv). In total, ATTRv was detected in 7 individuals (3 with a presymptomatic mutation of the disease), 16 patients with age-related ATTR and 31 individuals with unknown cardiac amyloidosis with the tests performed, which confirms the presence of this disease in non-endemic areas. CONCLUSIONS: ATTR is a disease that must be taken into account in the differential diagnosis of patients with heart failure with preserved LVEF, especially if associated with neurological symptoms.

Atypical presentation of transthyretin amyloidosis in a non-endemic area. / Presentación atípica de amiloidosis por transtiretina en un área no endémica.

BACKGROUND AND OBJECTIVE: There are 2 types of amyloidosis caused by transthyretin deposits: the wild type (wt-ATTR) and the mutant type (m-ATTR), transmitted by autosomal dominant inheritance with variable penetrance, manifesting with neurological and/or cardiac symptoms. We report on 3 families affected by m-ATTR diagnosed in a nonendemic area. MATERIAL AND METHODS: We studied 63 patients with a high suspicion of ATTR. The diagnosis was subsequently performed by magnification through polymerase chain reaction of DNA. For the positive cases, we studied the first-degree relatives. RESULTS: We detected 7 positive cases of m-ATTR, distributed among 3 families (Glu74Gln, Val142Ile in heterozygosity and Val142Ile in homozygosity), and 3 cases of nonpathogenic variants. CONCLUSIONS: Hereditary ATTR is a rare disease but is present in nonendemic areas and should therefore be considered in the differential diagnosis of patients with polyneuropathy and/or heart failure with preserved ejection fraction.