COL9A3 Gene

Intervertebral disc disease is a common condition characterized by the breakdown (degeneration) of one or more of the discs that separate the bones of the spine (vertebrae), causing pain in the back or neck and frequently in the legs and arms. The intervertebral discs provide cushioning between vertebrae and absorb pressure put on the spine.

While the discs in the lower (lumbar) region of the spine are most often affected in intervertebral disc disease, any part of the spine can have disc degeneration. Depending on the location of the affected disc or discs, intervertebral disc disease can cause periodic or chronic pain in the back or neck. Pain is often worse when sitting, bending, twisting, or lifting objects.

Degenerated discs are prone to out-pouching (herniation); the protruding disc can press against one of the spinal nerves that run from the spinal cord to the rest of the body. This pressure causes pain, weakness, and numbness in the back and legs. Herniated discs often cause nerve pain called sciatica that travels along the sciatic nerve, which runs from the lower back down the length of each leg.

As a disc degenerates, small bony outgrowths (bone spurs) may form at the edges of the affected vertebrae. These bone spurs may pinch (compress) the spinal nerves, leading to weakness or numbness in the arms or legs. If the bone spurs compress the spinal cord, affected individuals can develop problems with walking and bladder and bowel control. Over time, a degenerating disc may break down completely and leave no space between vertebrae, which can result in impaired movement, pain, and nerve damage.

Multiple epiphyseal dysplasia is a disorder of cartilage and bone development primarily affecting the ends of the long bones in the arms and legs (epiphyses). There are two types of multiple epiphyseal dysplasia, which can be distinguished by their pattern of inheritance. Both the dominant and recessive types have relatively mild signs and symptoms, including joint pain that most commonly affects the hips and knees, early-onset arthritis, and a waddling walk. Although some people with multiple epiphyseal dysplasia have mild short stature as adults, most are of normal height. The majority of individuals are diagnosed during childhood; however, some mild cases may not be diagnosed until adulthood.

Recessive multiple epiphyseal dysplasia is distinguished from the dominant type by malformations of the hands, feet, and knees and abnormal curvature of the spine (scoliosis). About 50 percent of individuals with recessive multiple epiphyseal dysplasia are born with at least one abnormal feature, including an inward- and upward-turning foot (clubfoot), an opening in the roof of the mouth (cleft palate), an unusual curving of the fingers or toes (clinodactyly), or ear swelling. An abnormality of the kneecap called a double-layered patella is also relatively common.