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Legius Syndrome (SPRED1) Deletion/Duplication
2008373
Ordering Recommendation

This is a second tier test and REQUIRES PERMISSION from  ARUP's Genetic Counselor (800-242-2787, x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.

Mnemonic
LS DD
Methodology
Multiplex Ligation-dependent Probe Amplification
Performed
Varies
Reported
Within 14 days
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 (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 2 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
Always consult with Fragment Analysis technical supervisor (ext. 2320) or technical liaison (est. 4429).
Plasma, buccal brush or swab, FFPE tissue, fresh/frozen tissue. 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
By report
Interpretive Data
Background Information for Legius Syndrome (SPRED1) Deletion/Duplication:
Characteristics:
Cafe au lait spots, axillary and inguinal freckling, learning disabilities 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:
Multiplex ligation-dependent probe amplification (MLPA) to detect large SPRED1 locus and intragenicdeletions/duplications.
Analytical Sensitivity and Specificity: 99 percent.
Limitations
: Diagnostic errors can occur due to rare sequence variations. Breakpoints for large deletions/duplications will not be determined. SPRED1 base pair substitutions, small deletions/duplications, deep intronic, and regulatory region mutations 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)
81479
Components
Component Test Code*Component Chart NameLOINC
2008374Legius Syndrome (SPRED1) DelDup Specimen
2008375Legius Syndrome (SPRED1) DelDup 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
  • SPRED1 deletion/duplication assay