Ordering Recommendation

Confirms a diagnosis of hypochondroplasia in individuals with clinical or radiological evidence of the condition.

Mnemonic
HYPOCH
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Mon, Thu

Reported

Within 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

By report

Interpretive Data

Background Information for Hypochondroplasia (FGFR3) 2 Mutations:
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 percent 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 or c.1620C>G will not be detected. Diagnostic errors can occur due to rare sequence variations.
Analytic Sensitivity and Specificity:
99 percent
Clinical Sensitivity:
70 percent

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
Components
Component Test Code* Component Chart Name LOINC
0051385 Hypochondroplasia (FGFR3) 2 Mutations
2001326 Hypochondroplasia (FGFR3), Specimen
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Aliases
  • FGFR3 molecular assay
Hypochondroplasia (FGFR3) 2 Mutations