Confirm clinical diagnosis of Loeys-Dietz syndrome.
Polymerase Chain Reaction/Sequencing
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Background Information for Loeys-Dietz Syndrome (TGFBR1 & TGFBR2) Sequencing:
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 genes coding regions and intron-exon boundaries.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletion/duplications will not be detected.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|2002706||LDS FGS Specimen|
|2002707||Loeys-Dietz Syndrome Sequencing|
- LDS sequencing assay
- TGBR1, TGBR2 sequencing assay