NF1 Sequencing and Deletion/Duplication

This test is used to identify individuals with autosomal dominant neurofibromatosis type 1 (NF1) syndrome. It detects single-nucleotide variants, deletions, and duplications in the NF1 gene, which encodes the neurofibromin protein. Sample reports and information regarding the specific variants analyzed for each gene are available on our website QuestHereditaryCancer.com.

If a familial mutation in the NF1 gene has been detected by sequencing or deletion/duplication studies, the Hereditary Cancer Single Site(s) test (test code 93945) may be considered to only test for the designated familial mutation. Official test results of the family member must be available for laboratory review. For more information, please visit our website QuestHereditaryCancer.com. To discuss a family history with a Quest Diagnostics genetic counselor, please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463).

While a diagnosis of NF1 syndrome is typically made based on available clinical diagnostic criteria (below), molecular genetic testing of the NF1 gene may be appropriate to help confirm a suspected diagnosis under certain circumstances, such as when only one diagnostic feature is observed in a young child.¹

A diagnosis of NF1 syndrome is made for individuals with 2 or more of the following features²:

• Six or more café au lait macules >5 mm in greatest diameter in prepubertal individuals, or >15 mm in greatest diameter in post-pubertal individuals
• Two or more neurofibromas of any type, or 1 plexiform neurofibroma
• Freckling in the axillary or inguinal regions
• Optic glioma
• Two or more Lisch nodules (iris hamartomas)
• A distinctive osseous lesion such as sphenoid dysplasia or tibial pseudarthrosis
• A first-degree relative (parent, sib, or offspring) with NF1 as defined by the above criteria

If molecular genetic testing is pursued, informed consent following genetic counseling is strongly recommended.

For more information or to discuss a family history with a Quest genetic counselor, please call
Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463).

The right time is different for every individual. An individual’s current medical status, personal experience with symptoms of NF1 syndrome, and general readiness for genetic information all influence the decision to be tested. Having an open dialogue with individuals about these topics can assist with shared decision-making.

Upon receipt of a fully completed order, our team will verify coverage with your patient’s healthcare insurance plan and estimate their likely out-of-pocket responsibility. If your patient’s estimated responsibility is over $100, we will notify you and/or your patient prior to test initiation to discuss options for continuation or cancellation of the test. Please note that orders lacking complete information will not be processed.

On average, results will be completed 14 to 21 days after receipt of the sample in the laboratory if the family history form and order are complete and the health plan does not require preauthorization. Turnaround time may vary based on delays caused by incomplete orders or insurance authorizations.

Individuals with a positive result have a pathogenic or likely pathogenic variant in the NF1 gene, which confirms a diagnosis of NF1 syndrome.^1,2 A positive result does not mean that an individual has a diagnosis of all features associated with NF1 syndrome or that they will definitely develop these in their lifetime. Specific risk information will be provided in the result report, and you can visit our website at QuestHereditaryCancer.com for more information.

Clinical management guidelines are available for individuals with a positive result.^1,2

A negative result means that a pathogenic or likely pathogenic variant was not detected in the NF1 gene. For more information regarding specific genetic variants analyzed in this assay please refer to the methods and limitations section of the genetic testing report. Clinical diagnostic criteria are available if an individual is still suspected of having a diagnosis of NF1 syndrome in the context of a negative genetic testing result.¹

A VUS result means that the variant has not been previously described in the literature or that the clinical significance is unclear based upon currently available evidence. Medical management decisions should be based on personal and family history. Family studies may help to learn more about the clinical significance of this variant. The classification and interpretation of the variant(s) identified reflect the current state of Quest’s understanding at the time of the report. Variant classification and interpretation are subject to professional judgment and may change for a variety of reasons including, but not limited to, updates in classification guidelines and availability of additional scientific and clinical information. It is important to check in with the laboratory annually for variant updates because new information regarding the variant and classification may become available over time. Please visit QuestDiagnostics.com/VariantIQ for information about variant classification. If you have questions, please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to speak with a genetic counselor.