Hypochondroplasia via the FGFR3 Gene
Summary and Pricing 
Test Method
Bi-Directional Sanger SequencingTest Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
---|---|---|---|---|---|
428 | FGFR3 | 81404 | 81404 | $560 | Order Options and Pricing |
Pricing Comments
CNV detection may be ordered through Test #600.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
Turnaround Time
4 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics 
Clinical Features
Hypochondroplasia (OMIM#146000) is a relatively common skeletal dysplasia characterized by short stature; stocky build; disproportionately short arms and legs; broad, short hands and feet; mild joint laxity; and macrocephaly (Francomano. GeneReviews 2005). The skeletal features are very similar to achondroplasia but usually tend to be milder. Children usually present as toddlers or school-age children with failure to grow. Limb disproportion and other features become more prominent as age increases.
Genetics
Hypochondroplasia is inherited in an autosomal dominant manner. The majority of new cases result from a de novo variant. FGFR3 is the only gene known to be associated with hypochondroplasia; however, genetic heterogeneity is suspected. Two recurrent FGFR3 variants (c.1620C>A and c.1620C>G) resulting in p.Asn540Lys in exon 13 that encodes the ATP-binding segment of the tyrosine kinase domain have been shown to be common causes of hypochondroplasia (Bellus et al. Nat Genet 10:357–359, 1995; Prinos et al. Hum Mol Genet 4:2097–2101, 1995). Sequence analysis of FGFR3 exons 7, 9, 10, 13, and 15 detects other rare FGFR3 variants associated with hypochondroplasia. FGFR3 gene encodes fibroblast growth factor receptor-3, a member of the FGFR family. Like all of the FGFRs, FGFR3 is a membrane-spanning tyrosine kinase receptor with an extracellular ligand-binding domain consisting of three immunoglobulin subdomains, a transmembrane domain, and a split intracellular tyrosine kinase domain (Green et al. Bioessays 18:639–646. 1996).
Clinical Sensitivity - Sanger Sequencing
This test is predicted to detect disease variants in >70% of affected individuals (Prinos et al. Hum Mol Genet 4:2097–2101, 1995; Prinster et al. Am J Med Genet 75:109–112, 1998; Ramaswami et al. J Pediatr 133:99–102, 1998; Grigelioniene et al. Hum Mut 11:333, 1998; Bellus et al. Am J Hum Genet 67:1411–1421, 2000; Thauvin-Robinet et al. Am J Med Genet A 119:81–84, 2003).
Testing Strategy
This test involves bidirectional sequencing using genomic DNA of 5 selected coding exons (exon 7, 9, 10, 13, 15) of the FGFR3 gene plus ~10 bp of flanking non-coding DNA on each side. We will also sequence any single exon (Test #100) in family members of patients with a known variant or to confirm research results.
Indications for Test
Candidates for this test are patients with clinical features consistent with hypochondroplasia and family members of patients who have a known FGFR3 variant.
Candidates for this test are patients with clinical features consistent with hypochondroplasia and family members of patients who have a known FGFR3 variant.
Gene
Official Gene Symbol | OMIM ID |
---|---|
FGFR3 | 134934 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Hypochondroplasia | 146000 |
Related Tests
Citations 
- Bellus GA, McIntosh I, Smith EA, Aylsworth AS, Kaitila I, Horton WA, Greenhaw GA, Hecht JT, Francomano CA. 1995. A recurrent mutation in the tyrosine kinase domain of fibroblast growth factor receptor 3 causes hypochondroplasia. Nat. Genet. 10: 357–359. PubMed ID: 7670477
- Bellus, G. A., et.al. (2000). "Distinct missense mutations of the FGFR3 lys650 codon modulate receptor kinase activation and the severity of the skeletal dysplasia phenotype." Am J Hum Genet 67(6): 1411-21. PubMed ID: 11055896
- Francomano, Clair A MD, FACMG (2005). "Hypochondroplasia."
- Green, P. J., et.al. (1996). "Promiscuity of fibroblast growth factor receptors." Bioessays 18(8): 639-46. PubMed ID: 8760337
- Grigelioniene, G., et.al. (1998). "A novel missense mutation Ile538Val in the fibroblast growth factor receptor 3 in hypochondroplasia. Mutations in brief no. 122. Online." Hum Mutat 11(4): 333. PubMed ID: 10215410
- Prinos P, Costa T, Sommer A, Kilpatrick MW, Tsipouras P. 1995. A common FGFR3 gene mutation in hypochondroplasia. Human molecular genetics 4: 2097–2101. PubMed ID: 8589686
- Prinos P, Costa T, Sommer A, Kilpatrick MW, Tsipouras P. 1995. A common FGFR3 gene mutation in hypochondroplasia. Human molecular genetics 4: 2097–2101. PubMed ID: 8589686
- Prinster, C., et.al. (1998). "Comparison of clinical-radiological and molecular findings in hypochondroplasia." Am J Med Genet 75(1): 109-12. PubMed ID: 9450868
- Ramaswami, U., et.al. (1998). "Genotype and phenotype in hypochondroplasia." J Pediatr 133(1): 99-102. PubMed ID: 9672519
- Thauvin-Robinet, C., et.al. (2003). "Hypochondroplasia and stature within normal limits: another family with an Asn540Ser mutation in the fibroblast growth factor receptor 3 gene." Am J Med Genet A 119A(1): 81-4. PubMed ID: 12707965
Ordering/Specimens 
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
Specimen Types
Specimen Requirements and Shipping Details
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
STAT and Prenatal Test Options are not available with Patient Plus.
No Additional Test Options are available for this test.