Atypical presentation of transthyretin amyloidosis in a non-endemic area

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.

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.

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.

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.