ARUP's Laboratory Test Directory

Loeys-Dietz Syndrome (TGFBR1 & TGFBR2) Sequencing & Deletion/Duplication : 2002701
[ image for: Patient History for Loeys-Dietz Testing]
Patient History for Loeys-Dietz Testing
[ image for: Additional Technical Information]
Additional Technical Information


Mnemonic: LDS FGA

Ordering Recommendation: Diagnostic testing for Loeys-Dietz syndrome. Predictive testing for Loeys-Dietz syndrome.
Methodology: Polymerase Chain Reaction/Multiplex Ligation-dependent Probe Amplification/Sequencing
Performed: Varies
Reported: Within 35 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Interpretive Data: Background Information for Loeys-Dietz Syndrome (TGFBR1 & TGFBR2) Sequencing and Deletion/Duplication:
Characteristics of Loeys-Dietz Syndrome (LDS): Vascular-thoracic findings (thoracic, cerebral and abdominal arterial aneurysms and/or dissections), skeletal abnormalities (scoliosis, arachnodactyly, talipes equinovarus, joint laxity, pectus excavatum and carinatum), unusual craniofacial features (hypertelorism, craniosynostosis and cleft palate/bifid uvula) and cutaneous findings (translucent velvety skin, widened poorly-formed scars and easy bruising).
Incidence: Unknown, but rare, and seen in all ethnicities.
Inheritance: Autosomal dominant; 75 percent of mutations are de novo.
Penetrance: 99 percent.
Cause: Pathogenic TGFBR1 and TGFBR2 gene mutations.
Clinical Sensitivity: 95 percent.
Methodology: Bidirectional sequencing of the TGFBR1 and TGFBR2 coding regions and intron-exon boundaries. Multiplex ligation-dependent probe amplification (MLPA) of the entire TGFBR1 and TGFBR2 coding regions.
Analytical Sensitivity and Specificity of Sequencing: 99 percent.
Analytical Specificity of MLPA: 99 percent.
Limitations: Rare diagnostic errors can occur due to primer or probe site mutations. Regulatory region mutations and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
CPT Code(s): 81405 (2), 81479