splice donor site results in the loss of function at that site. This leads to the skipping of the exon and deletion of amino acids. The loss of these amino acids result in an abnormal procollagen II structure. The structure is not stable like the normal procollagen II structure and is normally degraded at a faster rate. Diagnosis Family/medical history Kniest dysplasia is an autosomal dominant condition. This means that the person only needs to have one copy of the mutated gene in order to have the condition. People with a family history are at a higher risk of having the disease than people with no family history. A random mutation in the gene can cause a person with no family history to also have the condition. Diagnostic techniques A combination of medical tests are used to diagnosis Kniest dysplasia. These tests can include: Computer Tomography Scan (CT scan) - This test uses multiple images taken at different angles to produce a cross-sectional image of the body. Magnetic Resonance Imaging (MRI) - This technique proves detailed images of the body by using magnetic fields and radio waves. EOS Imaging - EOS imaging provides information on how musculoskeletal system interacts with the joints. The 3D image is scanned while the patient is standing and allows the physician to view the natural, weight-bearing posture. X-rays - X-ray images will allow the physician to have a closer look on whether or not the bones are growing abnormally. The images taken will help to identify any bone anomalies. Two key features to look for in a patient with Kniest dysplasia is the presence of dumb-bell shaped femur bones and coronal clefts in the vertebrae. Other features to look for include: Platyspondyly (flat vertebral bodies) Kyphoscoliosis (abnormal rounding of the back and lateral curvature of the spine) Abnormal growth of epiphyses, metaphyses, and diaphysis Short tubular bones Narrowed joint spaces Genetic Testing - A genetic sample may be taken in order to closely look at the patient's DNA. Finding an error in the COL2A1 gene will help identify the condition as a type II chondroldysplasia. Treatment Because Kniest dysplasia can affect various body systems, treatments can vary between non-surgical and surgical treatment. Patients will be monitored over time, and treatments will be provided based on the complications that arise. Surgical Spinal Fusion for patients with severe kyphoscoliosis Extension Osteotomy to help treat progressive joint limitation