SNP Shot: Genomic Insights

Chordoma is a rare form of cancer that develops along the spinal column, from the skull base to the tailbone. These tumors are slow-growing and invade nearby bone and soft tissues. They have a tendency to return after treatment, and in roughly 40% of cases, the cancer spreads (metastasizes) to other parts of the body, most commonly the lungs.

About half of all chordomas are found at the base of the spine (sacrum), around one-third are located at the base of the skull (occiput), and the remaining cases occur in the neck (cervical), upper back (thoracic), or lower back (lumbar) vertebrae. As the chordoma expands, it compresses the brain or spinal cord, causing characteristic symptoms. Regardless of location along the spine, a chordoma may cause pain, weakness, or numbness in the back, arms, or legs. Chordomas at the base of the skull (occipital chordomas) can lead to double vision (diplopia) and headaches. Chordomas in the tailbone area (coccygeal chordomas) may cause a noticeable lump under the skin and potentially bladder or bowel dysfunction.

Chordomas are most common in adults between 40 and 70 years old. Approximately 5% of chordomas are diagnosed in children. Males are affected approximately twice as often as females, for reasons not yet fully understood.

Inheritance:

When a chordoma develops due to an inherited duplication of the TBXT gene, only one copy of the altered gene in each cell is enough to elevate the risk of developing the condition. This is known as autosomal dominant inheritance. Individuals who inherit this duplication have a higher risk of developing the condition, not the condition itself. Other chordoma cases are sporadic, meaning they arise in individuals with no family history of the condition.