Thanatophoric Dysplasia, Types 1 and 2 (FGFR3) 13 Mutations
0051506
Ordering Recommendation
Rule out thanatophoric dysplasia.
Mnemonic
TD PAN
Methodology
Polymerase Chain Reaction/Fragment Analysis
Performed
Sun-Sat
Reported
3-7 days  
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
  
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.  
Unacceptable Conditions
  
Remarks
  
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
   
Interpretive Data
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 20,000 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. Diagnostic errors can occur due to rare sequence variations.

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81479
Components
Component Test Code*Component Chart NameLOINC
0051507Thanatophoric Dysplasia I/II 
2001382Thanatophoric Dysplasia I/II Specimen 
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Fetal Thanatophoric dysplasia mutation assay
  • FGFR3 mutation assay
  • TD (Thanatophoric Dysplasia, Types 1 & 2 (FGFR3) 13 Mutations)