1. Homozygosity for the transthyretin-met30-gene in two Swedish sibs with familial amyloidotic polyneuropathy.
- Author
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Holmgren G, Haettner E, Nordenson I, Sandgren O, Steen L, and Lundgren E
- Subjects
- Adult, Female, Homozygote, Humans, Male, Middle Aged, Mutation, Pedigree, Prealbumin analysis, Prealbumin biosynthesis, Sweden, Amyloidosis genetics, Hereditary Sensory and Autonomic Neuropathies genetics, Hereditary Sensory and Motor Neuropathy genetics, Methionine genetics, Prealbumin genetics
- Abstract
Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant inherited disorder. Recent biochemical studies have revealed that amyloid protein in FAP of Japanese, Swedish and Portuguese origin mainly consists of a variant transthyretin (TTR) (formerly called prealbumin) with one amino acid substitution of methionine for valine at position 30. In a 56-year-old man with typical polyneuropathy, gastrointestinal problems and vitreous amyloid, we diagnosed homozygosity for the TTR-met30-gene using RFLP analysis. In a family study, a sister presented the same homozygous RFLP pattern; however, in a careful clinical investigation we were not able to demonstrate any of the typical symptoms of FAP, nor could we demonstrate amyloid deposits in a biopsy skin specimen. This is the first report of homozygosity for the TTR-met30-gene, and it shows that the mutation of the protein involved in amyloid formation may be necessary but is clearly not sufficient for the clinical symptoms.
- Published
- 1988
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