A DNA polymorphic site, 5' to the serum amyloid P component gene, has been found to be significantly associated with amyloidosis in juvenile arthritic patients.
This is the sixth prealbumin variant implicated in amyloidosis, and adds to the accumulating evidence that the prealbuminamyloidoses are more varied and prevalent than previously thought.
These observations indicate the same methionine for valine substitution at position 30 of the transthyretin molecule in patients with vitreous amyloidosis as seen in Swedish patients with FAP as well as in patients with FAP from Japan and Portugal, and patients of Swedish descent with FAP from the United States.
The effects of 4 proteolytic enzymes, alpha-chymotrypsin, bromeline, collagenase, and lysozyme on amyloid tissue sections from a patient with familial amyloidotic polyneuropathy (FAP) were evaluated.
AmyloidB-protein/amyloid A4 is a peptide present in the neuritic plaques, neurofibrillary tangles and cerebrovascular deposits in patients with Alzheimer's disease and Down's syndrome (trisomy 21) and may be involved in the pathogenesis of Alzheimer's disease.
Overexpression of amyloid precursor protein A4 (beta-amyloid) immunoreactivity in genetically transformed cells: implications for a cellular model of Alzheimer amyloidosis.
Whereas in Down's syndrome, over-expression of the gene coding for PreA4 is likely to be responsible for the premature development of cerebral amyloidosis, a similar mechanism is yet to be demonstrated in Alzheimer's disease.
A variant of cystatin C lacking the first NH2-terminal residues and having one amino acid substitution at position 68 forms amyloid deposits mainly in the walls of brain arteries, causing fatal strokes in Icelandic patients with familial cerebral hemorrhage secondary to a form of an autosomal dominant amyloidosis.
To date, seven different single amino acid mutations in the plasma protein prealbumin (transthyretin) have been found to be associated with amyloidosis and each is the result of a single nucleotide change in the prealbumin gene.
The amyloid forming beta-peptide of Alzheimer's disease is synthesized as part of a larger integral membrane precursor protein (beta APP) of which three alternatively spliced versions of 695, 751, and 770 amino acids have been described.
Thus, the behavior of the transmissible brain amyloidosis parallels completely that of the transthyretinamyloidoses causing familial amyloidotic polyneuropathy, in which there are 19 different point mutations, each one of which increases enormously the likelihood of configurational change of transthyretinprealbumin to amyloid.
The gelsolin fragments isolated from at least one patient with amyloidosis have been reported to have an amino acid substitution, with asparagine replacing aspartic acid at position 187 of the plasma gelsolin.