Day 1: 3rd Annual Achondroplasia Research Conference recap
Day 1
First to take the stage was Dr. William G. Mackenzie, MD, FRCSC, Chairman, Department of Orthopaedics at Nemours/Alfred I. duPont Hospital for Children
Dr. Mackenzie set the perfect tone for the conference by delivering a comprehensive summary of achondroplasia and hypochondroplasia. He was friendly, welcoming and informative. From his opening presentation, we took away the following insights:
- Hypochondroplasia is a milder form of achondroplasia. The FGFR3 gene causes both hypochondroplasia and achondroplasia. What separates the two is that the mutation of the FGFR3 gene and pathway occurs in a different location along the FGFR3 gene in Hypochondroplasia.
- The spine of an achondroplasia patient isn’t a shorter length than an average person’s. In fact, the spine is of similar length. Researchers currently don’t know why the growth plates in the spine aren’t affected.
- In 60% of cases, those with achondroplasia have a compressed spinal cord at the base of the skull. The spine gets narrower as it goes down, which results in spinal stenosis. Bending the head and neck forward or extending them backwards compresses the spine. Sadly, about 30% of achondroplasia patients need surgery to decompress the spine.
- Bowed legs are very common. In fact, over 75% of achondroplasia patients experience them, which results in knee pain and a gait amongst other complications. Again, researchers aren’t sure why this occurs.
- If one of a patient’s growth plates in his or her legs is growing faster than the other, doctors can tether that growth plate so that the other can catch up, evening leg length over time. This is called growth modulation or guided growth.
- In achondroplasia patients, the mid-face doesn’t grow as well. This results in crowding of the teeth and a certain bite. Dr. Mackenzie encouraged patients with dental problems to get the help they needed in a hospital instead of a dentist office in case teeth extraction is needed.
After bidding us farewell, Dr. Mackenzie passed the baton and stage to Andrew Dauber, MD, MMSc, Chief of Endocrinology at Children’s National Hospital.
Dr. Dauber informed us that endocrinologists can make a positive difference in the growth rates of achondroplasia patients. This can help those who experience the personal challenges that short stature brings. He explained that there are thousands of genes involved in bone growth, and elaborated on why the focus of healthcare professionals and researchers has shifted to the growth plate; all the genes and pathways involved in bone growth are found there! We thoroughly enjoyed Dr. Dauber’s presentation and learned the following insights:
- It has been shown that a hormone called CNP (c-type natriuretic peptide) increased growth in the growth plate of rat models. When CNP was added to the models’ growth plate, more cartilage was made, leading to lengthening in the growth plate.
- The overexpression of CNP results in tall stature. People with overexpressed CNP have:
- o Tall, long limbs
o Big, long toes and fingers
o More severe Scoliosis
o Grow to be over 7 feet tall - The opposite is also true. CNP under expression results in short stature. Since patients with overexpressed CNP are otherwise healthy and free of cancer or heart failure, researchers believe that giving short stature patients CNP would be a safe option to promote growth in the growth plate.
- In achondroplasia and hypochondroplasia, the FGFR3 gene actively hinders growth. Researchers believe that by adding more CNP into the growth plate, patients can grow freely as CNP blocks the damaging FGFR3 pathway. Other rare diseases, such as Noonan Syndrome that causes short stature, could also use this approach.
