ARUP's Laboratory Test Directory
| 0051508: Thanatophoric Dysplasia, Types 1 & 2 (FGFR3) 13 Mutations, Fetal |
![[ image for: Time Sensitive]](icon_1.jpg){kind=icon} | Time Sensitive | ![[ image for: Patient History for Fetal Molecular Testing]](icon_29.jpg){kind=icon} | Patient History for Fetal Molecular Testing |
| Test Mnemonic: TD PAN FE | |
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Methodology: Polymerase Chain Reaction/Fragment Analysis
Performed: Sun-Sat Reported: 3-7 days |
| Specimen Required: | |
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Collect: Collect and Transport: Cultured cells: Two T-25 flasks at 80% confluent of cultured amniocytes. Fill flasks with culture media to ship at 20-25°C. Backup cultures must be retained at the client's institution until testing is complete. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787. Maternal specimens: One 3 mL whole blood lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B) at 20-25°C. Remarks: Fetal specimens are CRITICAL AMBIENT and must be received within 48 hours of shipment due to lability of cells. Maternal specimen is recommended for proper test interpretation. Order Maternal Cell (MCC MAT) (0050608). Patient History Form is available on the ARUP Web site or by contacting ARUP Client Services. Stability: Fetal: Ambient: 2 days; Refrigerated: Unacceptable; Frozen: Unacceptable Maternal: Ambient: 3 days; Refrigerated: 1 week; Frozen: Unacceptable |
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| Interpretive Data: | |
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Interpretive Data: Background information for Thanatophoric Dysplasia, Types I and II (FGFR3) 13 Mutations, Fetal 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. For quality assurance purposes, ARUP Laboratories will provide a confirmation of the above result at no charge. Following delivery, please collect a cord blood sample from the infant in a lavender (EDTA) or yellow (ACD Solution A or B) tube. Please specify on the test request form that this is a confirmatory study to be performed at no charge. Please provide the mother's name for specimen identification purposes. 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. FCC: 83900 Multiplex amplification; 83901 x14 Additional amplification; 83909 Capillary electrophoresis. For MCC Maternal cell (0050608) add: 83890 Isolation; 83900 Multiplex amplification; 83901 x14 Additional amplification; 83909 Capillary electrophoresis; 83912 Interpretation and report - Additional CPT Codes may be required for procedures performed to test for oncologic or inherited disorders. |