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Neurofibromatosis Type 1 (NF1) Sequencing and Deletion/Duplication
2007154
Ordering Recommendation

Preferred test to confirm a suspected diagnosis of neurofibromatosis type 1 (NF1) for individuals not meeting NIH clinical criteria.

Mnemonic
NF1 FGA
Methodology
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed
Varies
Reported
28-35 days
New York DOH Approval Status
This test is New York DOH approved.
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
 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Background Information for Neurofibromatosis Type 1 (NF1) Sequencing and Deletion/Duplication:
Characteristics:
Neurofibromatosis type 1 (NF1) demonstrates extreme clinical variability. Features include: cafe au lait macules, axillary and inguinal freckling, dermal fibromas, Lisch nodules (iris hamartomas), optic glioma, specific osseous lesions such as tibial pseudarthrosis or sphenoid dysplasia, learning disabilities (50 percent), scoliosis, vertebral dysplasia, and somatic overgrowth. Large NF1 locus deletions increase the risk for neurofibroma development, cognitive abnormalities and malignant peripheral nerve sheath tumors (MPNST).
Incidence:
1 in 3000.
Inheritance:
Autosomal dominant; de novo mutations occur in 50 percent of cases.
Penetrance:
100 percent by adulthood.
Cause
: Pathogenic NF1 mutations.
Clinical Sensitivity:
Approximately 84-93 percent; 77-86 percent of causative mutations are detected by sequencing and 7 percent by deletion testing.
Methodology:
Bidirectional sequencing of the entire NF1 coding region and intron-exon boundaries; multiplex ligation-dependent probe amplification (MLPA) to detect large NF1 locus and intragenicdeletions/duplications.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected. Large deletions/duplications of exons 11 and 20 will not be detected. The breakpoints of large deletions/duplications will not be determined.

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.

Components
Component Test Code*Component Chart NameLOINC
2007155Neurofibromatosis 1 (NF1)Seq,DelDup Spec31208-2
2007156Neurofibromatosis 1 (NF1)Seq,DelDup Int21717-4
* 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
  • NF
  • NF1 Sequencing and Deletion/Duplication
  • Von Recklinghausen's Neurofibromatosis (NF1) Sequencing and Deletion/Duplication