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Familial Transthyretin Amyloidosis (TTR) Sequencing
2014035
Ordering Recommendation

Confirm a clinical diagnosis of familial transthyretin (TTR) amyloidosis, familial euthyroid hyperthyroxinemia, or senile systemic amyloidosis.

Mnemonic
TTR FGS
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Sun-Sat
Reported
Within 2 weeks
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), Pink (K2 EDTA). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Interpretive Data: Background Information for Familial Transthyretin Amyloidosis (TTR) Sequencing:
Characteristics
: Familial Transthyretin Amyloidosis is caused by pathogenic variants of the TTR gene resulting in abnormal amyloid accumulation in various tissues and is generally categorized into three phenotypes: 1) familial amyloid polyneuropathy, a slowly progressive sensorimotor and autonomic neuropathy; 2) familial amyloid cardiomyopathy, a restrictive cardiomyopathy with cardiomegaly, conduction block, angina, congestive heart failure and aortic dissection/dilatation; and 3) leptomeningeal amyloidosis, primarily affecting the CNS, causing dementia, visual impairment, seizures, ataxia, psychosis, hemorrhage, and hydrocephalus. TTR variants can also be associated with benign familial euthyroid hyperthyroxinemia.
Incidence: 1 in 568 individuals from Northern Portugal; 1 in 100,000 individuals of Northern European ancestry.
Inheritance: Autosomal dominant.
Penetrance: Incomplete.
Cause: Pathogenic TTR gene variants.
Clinical Sensitivity: 99 percent for Familial TTR Amyloidosis.
Methodology: Bidirectional sequencing of all coding regions and intron-exon boundaries of the TTR gene.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region variants, deep intronic variants and large deletions/duplications in TTR will not be detected.

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
CPT Code(s)
81404
Components
Component Test Code*Component Chart NameLOINC
2014036TTR FGS Spec31208-2
2014037TTR FGS Interpretation48033-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Amyloidosis
  • Polyneuropathy