Diagnostic testing for Freeman-Sheldon syndrome.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: "Whistler appearance" due to facial muscle contractures, joint contractures of hands and feet, facial dysmorphism, strabismus, dental crowding, restricted cervical flexion, scoliosis, hearing loss, cryptorchidism and inguinal hernia.
Prevalence: Uncertain; approximately 100 cases have been reported to date.
Inheritance: Autosomal dominant.
Cause: Pathogenic MYH3 gene mutations.
Clinical Sensitivity: Approximately 70 percent.
Methodology: Bidirectional sequencing of MYH3 exon 17 which includes the two most common mutations, R672C and R672H.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:Diagnostic errors can occur due to rare sequence variations. Mutations outside exon 17 will not be detected.
|Component Test Code*||Component Chart Name||LOINC|
|2002663||FSS SEQ Specimen|
|2002664||Freeman-Sheldon Syndrome Interpretation|
- Whistling Face Syndrome