Thanatophoric Dysplasia (TD) via the FGFR3 Gene
Summary and Pricing 
Test Method
Bi-Directional Sanger Sequencing
| Test Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
|---|---|---|---|---|---|
| 426 | FGFR3 | 81479 | 81479 | $520 | 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
Thanatophoric dysplasia (TD) is a short-limb dwarfism syndrome that is usually lethal in the perinatal period. TD is divided into type I (OMIM #187600), characterized by micromelia with bowed femurs and, uncommonly, the presence of cloverleaf skull deformity of varying severity; and type II (OMIM #187601), characterized by micromelia with straight femurs and the uniform presence of moderate-to-severe cloverleaf skull deformity (Karczeski & Cutting. GeneReviews. 2008). Other features common to type I and type II include: short ribs, narrow thorax, macrocephaly, distinctive facial features, brachydactyly, hypotonia, and redundant skin folds along the limbs. Most affected infants die of respiratory insufficiency shortly after birth. Rare long-term survivors have been reported.
Genetics
Thanatophoric dysplasia (TD) is inherited in an autosomal dominant manner with complete penetrance. The majority of probands have a de novo gene variant. FGFR3 is the only gene known to be associated with TD type I and type II. A single FGFR3 variant (p.Lys650Glu) in exon 15 has been identified in all individuals with TD type II (Bellus et al. Am J Hum Genet 67:1411–1421, 2000). Sequence analysis of selected exons of FGFR3 (exons 7, 10, 15, and 19 for TD type I; and exon 15 for TD type II) detects up to 99% disease variants causing TD type I and >99% of variants causing TD type II (Wilcox et al. Am J Med Genet 78:274–281, 1998; Brodie et al. Am J Med Genet 84:476–480, 1999; Camera et al. Am J Med Genet 104:277–281, 2001). 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 up to 99% of disease variants causing TD type I and >99% of variants causing TD type II (Wilcox et al. 1998; Brodie et al. 1999; Camera et al. 2001).
Testing Strategy
This test involves bidirectional sequencing using genomic DNA of 4 selected coding exons (exon 7, 10, 15, 19) 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 newborns with abnormal clinical and radiologic features consistent with TD, and patients with abnormal prenatal ultrasound results showing features suggestive of TD in the fetus.
Candidates for this test are newborns with abnormal clinical and radiologic features consistent with TD, and patients with abnormal prenatal ultrasound results showing features suggestive of TD in the fetus.
Gene
| Official Gene Symbol | OMIM ID |
|---|---|
| FGFR3 | 134934 |
| Inheritance | Abbreviation |
|---|---|
| Autosomal Dominant | AD |
| Autosomal Recessive | AR |
| X-Linked | XL |
| Mitochondrial | MT |
Diseases
| Name | Inheritance | OMIM ID |
|---|---|---|
| Thanatophoric Dysplasia Type 1 | 187600 | |
| Thanatophoric Dysplasia Type 2 | 187601 |
Related Tests
Citations
- 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
- Brodie, S. G., et.al. (1999). "Platyspondylic lethal skeletal dysplasia, San Diego type, is caused by FGFR3 mutations." Am J Med Genet 84(5): 476-80. PubMed ID: 10360402
- Brodie, S. G., et.al. (1999). "Platyspondylic lethal skeletal dysplasia, San Diego type, is caused by FGFR3 mutations." Am J Med Genet 84(5): 476-80. PubMed ID: 10360402
- Camera, G., et.al. (2001). "Occurrence of thanatophoric dysplasia type I (R248C) and hypochondroplasia (N540K) mutations in two patients with achondroplasia phenotype." Am J Med Genet 104(4): 277-81. PubMed ID: 11754059
- Camera, G., et.al. (2001). "Occurrence of thanatophoric dysplasia type I (R248C) and hypochondroplasia (N540K) mutations in two patients with achondroplasia phenotype." Am J Med Genet 104(4): 277-81. PubMed ID: 11754059
- Green, P. J., et.al. (1996). "Promiscuity of fibroblast growth factor receptors." Bioessays 18(8): 639-46. PubMed ID: 8760337
- Karczeski, Barbara MS (2008). "Thanatophoric Dysplasia."
- Wilcox, W. R., et.al. (1998). "Molecular, radiologic, and histopathologic correlations in thanatophoric dysplasia." Am J Med Genet 78(3): 274-81. PubMed ID: 9677066
- Wilcox, W. R., et.al. (1998). "Molecular, radiologic, and histopathologic correlations in thanatophoric dysplasia." Am J Med Genet 78(3): 274-81. PubMed ID: 9677066
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
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ORDER OPTIONS
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