ARUP's Laboratory Test Directory

Noonan Syndrome (PTPN11) Sequencing : 0051805
[ image for: Patient History for Noonan or Leopard Syndrome Testing]
Patient History for Noonan or Leopard Syndrome Testing
  


Mnemonic: PTPN11 FGS

Ordering Recommendation: Diagnostic testing for Noonan syndrome.
Methodology: Polymerase Chain Reaction/Sequencing
Performed: Varies
Reported: Within 21 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:
Characteristics of Noonan Syndrome (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.
Characteristics of LEOPARD syndrome:
Lentigines, ECG abnormalities, ocular hypertelorism, pulmonary stenosis, abnormal genitalia, retardation of growth, and deafness.
Incidence:
1 in 1000 to 1 in 2500 for NS; rare for LEOPARD syndrome.
Inheritance:
Autosomal dominant.
Penetrance:
Unknown.
Cause of NS:
Deleterious mutations in PTPN11, SOS1, RAF1, KRAS and other unidentified genes.
Cause of LEOPARD syndrome:
Mutations in PTPN11 exons 7 and 12 as well as other unidentified genes.
Gene tested:
PTPN11.
Clinical Sensitivity:
50 percent of NS is due to PTPN11 mutations; unknown for LEOPARD syndrome.
Methodology:
Bidirectional sequencing of the entire PTPN11 coding region and intron-exon boundaries.
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, will not be detected.



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
Cross References: Leopard Syndrome (Noonan Syndrome (PTPN11) Sequencing) , PTPN11 , Full Gene Sequence, Blood (Noonan Syndrome (PTPN11) Sequencing)