Ordering Recommendation

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

Mnemonic
NF1 FGS
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Varies

Reported

21-28 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (K2EDTA), 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: 1 week; Refrigerated: 1 month; Frozen: 6 months

Reference Interval
Interpretive Data

Background Information for Neurofibromatosis Type 1 (NF1) Sequencing:
Characteristics:
Neurofibromatosis ty1 (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 77-86 percent of causative mutations are detected by sequencing.
Methodology:
Bidirectional sequencing of the entire coding region and intron-exon boundaries of the NF1 gene.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Mutations in genes other than NF1 are not evaluated. This assay is not designed to detect somatic variants associated with malignancy. Interpretation of this test result may be impacted if the patient has had an allogeneic stem cell transplantation.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81408

Components
Component Test Code* Component Chart Name LOINC
2007160 Neurofibromatosis I (NF1) Seq Specimen
2007161 Neurofibromatosis 1 (NF1) Seq 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
  • NF
  • NF1 sequencing assay
  • Von Recklinghausen's Neurofibromatosis (NF1) Sequencing
Neurofibromatosis Type 1 (NF1) Sequencing