A DNA test for Indiana/Swiss hereditary amyloidosis (FAP II)

Autosomal dominant amyloidosis of the Indiana/Swiss type is a late-onset disorder characterized by carpal tunnel syndrome, progressive peripheral neuropathy, vitreous deposits, and cardiomyopathy. This disorder was originally described in a large Indiana family of Swiss descent and is also known as familial amyloidotic polyneuropathy (FAP) type II. In the Indiana family, the genetic basis of the disease is a variant of plasma prealbumin (transthyretin), which has a serine-for-isoleucine substitution at amino acid 84 of the 127-residue prealbumin molecule. We predicted that the corresponding mutation in the prealbumin gene consisted of a T-to-G change in codon 84 (which created an AluI recognition site) and then demonstrated the extra AluI site in the DNA of patients by Southern blot analysis with a genomic prealbumin probe. This verifies the protein findings at the DNA level and provides a direct, reliable DNA test for the Ser-84 prealbumin gene associated with Indiana/Swiss hereditary amyloidosis.