Simplified method for screening populations at risk for transthyretin Met30-associated familial amyloidotic polyneuropathy.

This simple, reliable method for detecting the transthyretin-methionine30 [TTR(Met30)] mutation, found in patients with familial amyloidotic polyneuropathy (FAP), is based on production of an extra peptide fragment when the mutant TTR is treated with cyanogen bromide (CNBr). After electrophoresis of whole serum and excision of the TTR (prealbumin) band, the TTR-containing gel is incubated with CNBr, subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis, and stained with silver to determine whether an abnormal CNBr fragment (residues 31-127) is present. Results can be obtained within two days. Several samples can be processed simultaneously, and no unusual equipment or reagents are required. The procedure is suitable for routine diagnosis of FAP and for epidemiological studies.