Achondroplasia (FGFR3) 2 Mutations, Fetal
0051265
Ordering Recommendation
Rule out achondroplasia.
Mnemonic
AD PCR FE
Methodology
Polymerase Chain Reaction/Fluorescence Monitoring
Performed
Mon, Thu
Reported
2-7 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Fetal Specimen: Two T-25 flasks at 80% confluency of cultured amniocytes. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787. Or amniotic fluid.
AND Maternal Cell Contamination Specimen:
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Cultured Amniocytes: Fill flasks with culture media. Transport two T-25 flasks at 80% confluency of cultured amniocytes. Backup cultures must be retained at the client's institution until testing is complete.
OR Amniotic Fluid:
Transport 10 mL unspun fluid. (Min: 5 mL)
AND Maternal Cell Contamination Specimen:
Transport 3 mL whole blood. (Min: 1 mL)  
Storage/Transport Temperature
Cultured Amniocytes: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to liability of cells.
Amniotic fluid:
Room temperature.
Maternal Cell Contamination Specimen:
Room temperature.  
Unacceptable Conditions
 
Remarks
Maternal specimen is recommended for proper test interpretation. Order Maternal Cell Contamination. Patient History Form is available on the ARUP Web site or by contacting ARUP Client Services.  
Stability
Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Maternal Cell Contamination Specimen
: Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
By report
Interpretive Data
Background information for Achondroplasia (FGFR3) 2 Mutations, Fetal:
Characteristics:
Short stature with disproportionately short arms and legs, a large head, usually normal life span and intelligence; increased risk for death in infancy from compression of spinal cord and/or upper airway obstruction.
Incidence:
1:25,000.
Inheritance:
Autosomal dominant; 80 percent arise from de novo mutations.
Penetrance:
100 percent.
Cause:
Pathogenic FGFR3 gene mutation.
Clinical Sensitivity:
Two mutations, c.1138G>A and c.1138G>C, in the FGFR3 gene account for greater than 99 percent of cases.
Methodology:
PCR and fluorescent hybridization probes.
Analytical Sensitivity and Specificity:
Greater than 99 percent.
Limitations:
Mutations other than c.1138G>A and c.1138G>C will not be detected. Diagnostic errors can occur due to rare sequence variations.

For quality assurance purposes, ARUP Laboratories will confirm the above result at no charge following delivery. Order Confirmation of Fetal Testing and include a copy of the original fetal report (or the mother's name and date of birth) with the test submission. Please contact an ARUP genetic counselor at (800) 242-2787 extension 2141 prior to specimen submission.

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.

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81401; Fetal Cell Contamination (FCC): 81265;
Components
Component Test Code*Component Chart Name
0050548Maternal Cell Contamination, Fetal Spec
0050612Maternal Cell Contam, Maternal Spec
0051267Achondroplasia PCR
0051505Achondroplasia PCR Fetal 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.
Cross References