Thanatophoric dysplasia type 2

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Thanatophoric dysplasia, type 2 (TD2) is a form of TD (see this term) characterized by micromelia, straight long-bones, macrocephaly, brachydactyly, shortened ribs and a clover-leaf skull (kleeblattschaedel).

The prevalence is unknown but it is less common than TD1 (see this term).

TD2 presents in the prenatal period (in the first to second trimester) with micromelia, long-bones (femurs) that are straight and not as short as those seen in TD type 1, platyspondyly of the vertebrae, narrow thorax, and a cloverleaf (trilobed) skull. Distinctive facial features include macrocephaly, frontal bossing, low nasal bridge, large anterior fontanel and proptosis. Polyhydramnios is common. Neonates usually die shortly after birth due to respiratory insufficiency and/or spinal cord/brain stem compression.

TD2 is caused by a single missense mutation (K650E) in the fibroblast growth factor receptor 3 (FGFR3) gene, located to chromosome 4p16.3.

TD2 is inherited autosomal dominantly but the majority of cases are due to a de novo mutation in the proband. Genetic counseling allows families who have already had one child with TD2 to know that recurrence rate is about 2%, so their chance of having a healthy child is high. Expert reviewers: Dr. Michael Bober and Ms. Angie Duker

Visit the Orphanet disease page for more resources.

Last updated: 10/1/2013

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.