Legius Syndrome (SPRED1) Sequencing
2002945
Ordering Recommendation
Diagnostic testing for Legius syndrome.  Predictive testing for Legius syndrome.
Mnemonic
LS FGS
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
Within 21 days  
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
  
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
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
By report  
Interpretive Data
Background Information for Legius Syndrome (SPRED1) Sequencing
Characteristics:
Cafe au lait spots, axillary and inguinal freckling, learning disability and macrocephaly. Neurofibromas, lisch
nodules and CNS tumors are not observed.
Incidence:
Unknown; may represent 0.5 percent of neurofibromatosis type 1 diagnoses or 8 percent of those with isolated cafe au lait spots.
Inheritance:
Autosomal dominant.
Cause:
Pathogenic SPRED1 gene mutations
Clinical Sensitivity:
Unknown.
Methodology:
Bidirectional sequencing of the entire SPRED1 coding region and intron-exon boundaries.
Analytical Sensitivity and Specificity:
99 percent.
Limitations
: Some SPRED1 gene regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Diagnostic errors can occur due to rare sequence variations.



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  
Note
 
CPT Code(s)
81405
Components
Component Test Code*Component Chart Name
2002946Legius Syndrome Specimen
2002947Legius Syndrome Sequencing Interp
* 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
  • NF1-Like Syndrome Sequencing and (NF1) Sequencing Exon 22 (Exon 17))
  • SPRED1 sequencing
  • SPRED1 Sequencing and (NF1) Sequencing Exon 22 (Exon 17))