Facebook Pixel Code
Section banner image
Paediatric Laboratory Medicine

Skeletal Dysplasias: Thanatophoric Dysplasia

Clinical Significance

Thanatophoric dysplasia (TD) is one of the most common lethal skeletal dysplasias. TD is characterized by extremely short ribs, narrow thorax, tubular bones, hypotonia, brachydactyly, distinctive facial features, macrocephaly, a small chest which crowds the respiratory system, and compression of the brain due to deformations of the skull. Two types of TD exist: Type I based on the ab-sence of cloverleaf skull and a curved femur, and Type II based on the presence of a cloverleaf skull and a straight femur.

Test Name

Skeletal Dysplasias: Thanatophoric Dysplasia

Alternate Name/ Synonym

  • TD
  • Thanatophoric dwarfism

Gene Name

  • FGFR3

Test Code



Molecular Genetics


Targeted analysis of recurrent mutations

External Proficiency Testing


Turn Around Time

2 weeks (Prenatal samples), 2-3 weeks (Pregnancy/Urgent samples), 4-6 weeks (Routine)


Fibroblast growth factor receptor 3


Skeletal Dysplasias: Thanatophoric Dysplasia

Specimen Type

Blood; gDNA. 

For details about specimen requirements, please refer to: Specimen Type & Requirements (PDF).

Minimum Specimen Requirements

5-10 mL EDTA or ACD, 0.5 mL EDTA (neonate); minimum 10 ug in 100 uL low TE (pH8.0)


Room Temperature

Special Requirements

Special Instructions for Genome Diagnostics Samples

If sample shipment >48 hours, ship on ice.

Approval is not required

CPT Codes


Shipping and Contact Information

The Hospital for Sick Children
Rapid Response Laboratory
170 Elizabeth Street, Room 3642
Toronto, ON
M5G 2G3
Phone: 416-813-7200
Phone: 1-855-381-3212


Interpretation is provided in report

Information Sheet: Thanatophoric Dysplasia