What is thanatophoric dysplasia (thanatophoric dwarfism)?
Thanatophoric dysplasia is a rare genetic condition that affects bone development. It’s a type of skeletal dysplasia, a group of conditions that affect bone and cartilage growth. Another name for thanatophoric dysplasia is thanatophoric dwarfism.
There are two types of thanatophoric dysplasia:
- Type I (one): Children have curved thigh bones and flat spinal bones.
- Type II (two): Children have straight thigh bones and a unique skull shape called cloverleaf skull.
Thanatophoric dysplasia is a severe, life-threatening condition. Because it causes a very narrow chest and ribcage, babies born with thanatophoric dysplasia have difficulty breathing on their own. Many infants with thanatophoric dysplasia die shortly after birth.
Thanks to technological advances in medicine, some babies with the condition may survive past infancy. All children with thanatophoric dysplasia have long-term medical needs, including dependency on a ventilator for breathing and significant changes in neurologic function and development.
What causes thanatophoric dysplasia?
Thanatophoric dysplasia occurs because of a gene change (mutation) in the FGFR3 gene. This gene is responsible for making a protein that supports bone and brain tissue development.
The gene mutation that causes thanatophoric dysplasia happens due to random changes in the FGFR3 gene. It isn’t inherited, and the condition doesn’t tend to run in families.
What are the signs and symptoms of thanatophoric dysplasia?
All babies with thanatophoric dysplasia have extremely small stature. Those with type I may also have:
- A large skull
- Flattening in the top of the nose
- Pronounced forehead
- Protruding eyes
Babies with type II may have characteristics such as:
- Bowed legs
- Cloverleaf skull, a severe type of craniosynostosis
- Extremely short fingers and toes
- Narrow chest
- Small pelvis
- Very short or stunted limbs
How do we diagnose thanatophoric dysplasia?
We may see signs of thanatophoric dysplasia, such as extremely short limbs, during a prenatal ultrasound before birth. If we suspect thanatophoric dysplasia, we may order imaging tests, such as fetal MRIs or fetal echocardiograms.
Your provider may also recommend further testing to confirm the diagnosis, such as:
- Chorionic villus sampling (CVS) to test cells from your placenta for the FGFR3 gene mutation. We usually perform this in the first trimester.
- Amniocentesis to test amniotic fluid (the protective liquid surrounding your baby) for the FGFR3 gene mutation. We usually perform this after the first trimester.
Sometimes doctors diagnose thanatophoric dysplasia after birth. They may use tests such as:
- Blood tests to look for gene mutations
- X-rays to get a clear picture of your baby’s skeleton
How do we treat thanatophoric dysplasia?
Usually, thanatophoric dysplasia treatment includes palliative care. Our neonatal palliative care specialists offer services to help increase your baby’s comfort and allow you to spend quality time together. You may meet with the palliative care team before delivery to help identify goals before your baby goes to the Neonatal Intensive Care Unit (NICU).
Care for babies with thanatophoric dysplasia may also include:
Why choose us for treatment of thanatophoric dysplasia?
We deliver expertise and compassion for all your child’s needs. At the Colorado Fetal Care Center, we provide empathetic, advanced care for your baby before and after birth. In our Orthopedics Institute, you’ll receive care from some of the foremost pediatric skeletal dysplasia experts in the country.
Your treatment is in the hands of specialists who offer world-class testing, accurate diagnoses and compassionate care. We offer:
- Multispecialty care: We provide comprehensive, coordinated treatment for unborn babies suspected to have thanatophoric dysplasia. We bring all the necessary experts together in one convenient appointment and location. Fetal and pediatric surgeons, neonatologists, geneticists, psychologists and more are there to help you understand your baby’s diagnosis and treatment options. Our NICU treats more babies than almost any in the nation, so we have a wealth of experience helping families through this sensitive time. Those teams work seamlessly with our orthopedic and rehabilitation experts to make sure your child gets care designed just for them.
- Coordinated treatment: Before birth, our Colorado Fetal Care Center offers comprehensive genetic testing and state-of-the-art imaging to accurately diagnose genetic diseases such as thanatophoric dysplasia. After birth, your child receives care in our Skeletal Health and Dysplasia Program, where we offer specialized and empathetic care to provide comfort for your whole family. We’ll understand your goals and fully explain your child’s health and their treatment options.
- Supportive environment: Most babies born with thanatophoric dysplasia need immediate care at birth. We designed our Center so you can stay close to your baby throughout their treatment. Our Neonatal Palliative Care Program provides emotional, spiritual and physical support as you navigate complex decisions and spend time with your baby.
- Research emphasis: Our experts are constantly researching neonatal care and skeletal dysplasias. In many cases, we have been the first in the world to use new advanced therapies. We continually research new treatments to elevate care for our smallest, most vulnerable patients.
Contact us
Schedule an appointment with our Orthopedics Institute by calling 720-777-6600.
Schedule an appointment with the Colorado Fetal Care Center by calling 720-777-4463.
Helpful thanatophoric dysplasia resources