Sorted By Test Name - Mayo Medical Laboratories

AMYL
83667
AMYKM
83705
provided.
Reference Values:
This request will be processed as a consultation. An interpretive report will be provided.
Clinical References: 1. Vrana JA, Gamez JD, Madden BJ, et al: Classification of amyloidosis by
laser microdissection and mass spectrometry-based proteomic analysis in clinical biopsy specimens.
Blood 2009;114(24):4957-4959 2. Rodriguez FJ, Gamez JD, Vrana JA, et al: Immunoglobulin derived
depositions in the nervous system: novel mass spectrometry application for protein characterization in
formalin-fixed tissues. Lab. Invest. 2008;88(10);1024-1037 3. Picken MM: New insights into systemic
amyloidosis: the importance of diagnosis of specific type. Curr Opin Nephrol Hypertens 2007;16:196-203
4. Dispenzieri A, Gertz MA: The laboratory diagnosis and monitoring of amyloidosis. Communique
2002;27(9):1-10
Amyloidosis, Transthyretin-Associated Familial, DNA
Sequence, Blood
Clinical Information: The systemic amyloidoses are a number of disorders of varying etiology
characterized by extracellular protein deposition. The most common form is an acquired amyloidosis
secondary to multiple myeloma or monoclonal gammopathy of unknown significance (MGUS) in which
the amyloid is composed of immunoglobulin light chains. In addition to light chain amyloidosis, there are
a number of acquired amyloidoses caused by the misfolding and precipitation of a wide variety of
proteins. There are also hereditary forms of amyloidosis. Due to the clinical overlap between the acquired
and hereditary forms, it is imperative to determine the specific type of amyloidosis in order to provide an
accurate prognosis and consider appropriate therapeutic interventions. The most common hereditary
amyloidosis is familial transthyretin amyloidosis; an autosomal dominant disorder caused by mutations in
the transthyretin (TTR) gene. The resulting amino acid substitutions lead to a relatively unstable,
amyloidogenic TTR protein. Most individuals begin to exhibit clinical symptoms between the third and
seventh decades of life. Typically, TTR-associated amyloidosis is progressive over a course of 5 to 15
years and the most common cause of death is cardiomyopathy. Affected individuals may present with a
variety of symptoms, including peripheral neuropathy, blindness, cardiomyopathy, nephropathy,
autonomic nervous dysfunction, or bowel dysfunction. More than 90 mutations have now been identified
within the TTR gene which cause TTR-associated familial amyloidosis. Most of the mutations described
to date are single base pair changes that result in an amino acid substitution. Some of these mutations
correlate with the clinical presentation of amyloidosis. However, several different mutations have been
identified which exhibit considerable clinical overlap. It is important to note that this assay does not detect
mutations associated with non-TTR forms of familial amyloidosis. Therefore, it is important to first test
an affected family member to determine if TTR is involved and to document a specific mutation in the
family before testing at risk individuals.
Useful For: Diagnosis of adult individuals suspected of having transthyretin-associated familial
amyloidosis
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Benson MD: The hereditary amyloidoses. Best Pract Res Clin Rhematol
2003;17:909-927 2. Eneqvist T, Sauer-Eriksson AE: Structural distribution of mutations associated with
familial amyloidotic polyneuropathy in human transthyretin. Amyloid 2001;8:149-168 3. Connors LH,
Lim A, Prokaeva VA, et al: Tabulation of human transthyretin (TTR) variants, 2003. Amyloid
2003;10:160-184
Amyloidosis, Transthyretin-Associated Familial, Known
Mutation
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