ARUP's Laboratory Test Directory
| 0051506: Thanatophoric Dysplasia, Types I and II (FGFR3) 13 Mutations |
![[ image for: Patient History For Molecular Genetics]](icon_21.jpg){kind=icon} | Patient History For Molecular Genetics |
| Test Mnemonic: TD PAN | |
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Methodology: Polymerase Chain Reaction/Fragment Analysis
Performed: Sun-Sat Reported: 3-7 days |
| Specimen Required: | |
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Collect: One 3 mL lavender (EDTA), pink (K2EDTA) or yellow (ACD solution A or B).
Transport: 3 mL whole blood at 2-8°C. (Min: 1 mL) Pediatric Collection/Transport: 1 mL whole blood at 2-8°C. Stability: Ambient: 3 days; Refrigerated: 1 week; Frozen: Unacceptable |
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| Interpretive Data: | |
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Background information for Thanatophoric Dysplasia, Types I and II (FGFR3) 13 Mutations Characteristics: Micromelia, macrocephaly, short ribs and a narrow thorax; TD I has bowed femurs and TD II has straight femurs and a cloverleaf skull; death usually occurs from respiratory insufficiency within hours or days of birth. Incidence: 1 in 6,000 to 50,000 births. Inheritance: Autosomal dominant; arising from a de novo mutation. Cause: Fibroblast growth factor receptor 3 (FGFR3) gene mutations. Mutations tested: c.742C>T (R248C), c.746C>G (S249C), c.1108G>T (G370C), c.1111A>T (S371C), c.1118A>G (Y373C), c.2419T>G (X807G), c.2419T>A (X807R), c.2420G>T (X807L), c.2420G>C (X807S), c.2421A>T (X807C), c.2421A>C (X807C) and c.2421A>G (X807W) for TD I and c.1948A>G (K650E) for TD II. Clinical Sensitivity and Specificity: 99 percent. Methodology: Polymerase chain reaction (PCR) and single nucleotide extension followed by capillary electrophoresis. Analytic Specificity and Sensitivity: 99 percent. Limitations: Mutations other than those targeted in FGFR3 will not be detected; analytic sensitivity may be compromised by rare primer site mutations. This test is performed pursuant to an agreement with Roche Molecular Systems, Inc. Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com. Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory. |
| CPT Code(s): | |
| 83890 Isolation; 83900 Multiplex amplification; 83901 x2 Additional amplification; 83914 x9 Extension; 83909 Capillary electrophoresis; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders. |