Noonan Syndrome is an autosomal dominant disorder characterized by short stature, webbed neck and dysmorphic facial features including hypertelorism, downward slanting palpebral fissures and posteriorly rotated ears. A variety of congenital cardiac anomalies are also associated with Noonan Syndrome. Other manifestations include shield chest with pectus deformities, vertebral anomalies, bleeding diathesis and cryptorchidism in males. Noonan syndrome is genetically heterogeneous, with mutations in the PTPN11 gene accounting for approximately 50% of both familial and sporadic cases. The PTPN11 gene maps to chromosome 12q24.1 and encodes the non-receptor protein tyrosine phosphatase SHP-2. Diagnostic sequence analysis of PTPN11 coding region is available for patients with Noonan syndrome.

Reasons for Referral:

• Confirmation of diagnosis of Noonan syndrome
• Prenatal diagnosis only if a familial mutation is identified

Testing Methodology:

The PTPN11 gene coding region which contains fifteen exons is amplified by PCR, and direct sequencing is performed in both the forward and reverse directions using automated fluorescence dideoxy sequencing methods in a capillary electrophoresis format.

Sensitivity:

Technical: ~99% detection of mutations when present
Clinical: ~50% of Noonan Syndrome cases have PTPN11 mutations

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adults: 14 cc; Child: 6 cc; Infant: 2-3 cc
Requisition form must accompany specimen. Prior to any genetic testing, we recommend genetic counseling and request that the subject, or their legal guardian, sign our consent form and submit it with the sample. To receive our forms and information about prenatal testing, please contact our laboratory.

Turnaround Time:

4 weeks

CPT Codes and Prices:

Index: 83904x15, 83909x30, 83898x10, 83894, 83891
Known Familial Mutation: 83904x2, 83912, 83909x2, 83898, 83891, 83894

References:

1. Tartaglia M, et al. (2002) Nat. Genet. 29: 465-468.
2. Tartaglia M, et al. (2002) Am. J. Hum. Genet. 70: 1555-1563.
3. Maheshwari M, et al. (2002) Hum. Mutat. 20: 298-304.

Shipping Information

Forms:

 >> Gene Sequencing Requisition
 >> Prenatal Requisition

Test Codes:

Index: 6065
Known Familial Mutation: 6107
Prenatal (Known Familial Mutation Only): 6106

Medical Genetics Laboratories
Baylor College of Medicine · Houston, TX 77030
Phone: 1-800-411-GENE · Fax: 713-798-6584
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