ARUP's Laboratory Test Directory

0051367: Hypochondroplasia

Test Mnemonic: HYPOCH
Methodology: Polymerase Chain Reaction/Fluorescence Monitoring

Performed: Mon, Thu

Reported: Within 7 days

Specimen Required:  
Collect: Collect: One 3 mL lavender (EDTA) or pink (K2EDTA). Also acceptable: yellow (ACD Solution A), lt. blue (sodium citrate), or green (sodium or lithium heparin).

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

Reference Interval:
By report

Interpretive Data:
Background Information:
Characteristics: Short stature, stocky build, large head, shortening of the proximal or middle segments of the extremities, short broad hands and feet, limitation of elbow extension, and mild joint laxity. Phenotype not evident in infancy, becomes apparent in childhood.
Incidence: 1:15,000-40,000
Inheritance: Autosomal dominant; usually arising from a de novo mutation.
Cause: 70% of cases result from an A or G nucleotide substitution for C at 1620 in the FGFR3 gene.
Methods: PCR and fluorescent resonance energy transfer.
Limitations: Mutations in FGFR3 and other than c.1620C>A/G will not be detected.
Analytic Sensitivity and Specificity: 99%
Clinical Sensitivity: 70%

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; 83898 x2 Amplification; 83896 x4 Nucleic acid probes; 83912 Interpretation and report. Additional CPT code modifiers may be required for procedures to test for oncologic or inherited disorders.