ARUP's Laboratory Test Directory

Noonan Syndrome (PTPN11) Sequencing with Reflex to (SOS1) Sequencing : 2004189
[ image for: Patient History for Noonan or Leopard Syndrome Testing]
Patient History for Noonan or Leopard Syndrome Testing
[ image for: Additional Technical Information]
Additional Technical Information


Mnemonic: NS REFLEX

Ordering Recommendation: Diagnostic testing for Noonan syndrome.
Methodology: Polymerase Chain Reaction/Sequencing
Performed: Varies
Reported: Within 35 days
Specimen Required: 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.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Interpretive Data: Background Information for Noonan Syndrome (PTPN11) Sequencing with Reflex to (SOS1) Sequencing:
Characteristics of NS: Short stature, developmental delay, dysmorphic facial features, congenital heart disease, broad or webbed neck, superior pectus carinatum and inferior pectus excavatum, low-set nipples, cryptorchidism, coagulation, and lymphatic disorders.
Incidence: 1 in 1,000 to 1 in 2,500.
Inheritance: Autosomal dominant.
Penetrance: Unknown.
Cause of NS: Pathogenic mutations in PTPN11, SOS1, RAF1, KRAS and other unidentified genes.
Genes tested: PTPN11 and SOS1.
Clinical Sensitivity: Approximately 70 percent.
Methodology: Bidirectional sequencing of the entire PTPN11 coding region and intron-exon boundaries. If no known pathogenic mutations are detected, bidirectional sequencing of the SOS1 coding region and intron-exon boundaries is performed.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Rare diagnostic errors can occur due to primer site mutations. Regulatory region mutations, deep intronic mutations and large deletions/duplications will not be detected. Mutations in genes, other than PTPN11 and SOS1, will not be evaluated.



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
CPT Code(s): 81406; If reflexed, add 81406