Serum transthyretin (TTR) levels are low in familial amyloidotic polyneuropathy (FAP). also compared TTR concentrations in 12 African-Americans transporting the TTR V122I allele with those in 826 African-Americans who were homozygous wild type at the TTR locus. The TTR V122I carriers had significantly lower serum TTR concentrations than appropriate controls even though the majority of… Continue reading Serum transthyretin (TTR) levels are low in familial amyloidotic polyneuropathy (FAP).