Homozygosity for the transthyretin‐Met30‐gene in seven individuals with familial amyloidosis with polyneuropathy detected by restriction enzyme analysis of amplified genomic DNA sequences

Holmgren G, Bergström S, Drugge U, Lundgren E, Nording‐Sikström C, Sandgren O, Steen L. Homozygosity for the transthyretin‐Met30‐gene in seven individuals with familial amyloidosis with polyneuropathy detected by restriction enzyme analysis of amplified genomic DNA sequences. Clin Genet 1992:41:39–41. Familial amyloidotic polyneuropathy (FAP) with a mutation in position 30 of transthyretin (TTR) (previously called prealbumin) is an autosoma! dominant inherited disorder characterized by varying degrees of peripheral neuropathy, nephropathy, gastrointestinal problems, and vitreous amyloid. We have earlier diagnosed homozygosity for the TTR‐Met30‐gene using Southern analysis in four Swedish individuals. We have found it possible to detect homozygosity for the Met‐30 mutation by amplifying discrete regions of the TTR‐gene using polymerase chain reaction (PCR), and the amplification products restricted with Nsil analysed by gel electro‐phoresis. Clinical data on seven homozygous individuals, including three new cases, are presented.