Neanderthals that interbred with our ancestors may have passed on DNA that causes some people to develop a potentially fatal condition where the brain bulges out of the skull, a new study finds.
The disorder, known as Chiari malformation type I, affects the lower part of the cerebellum, the part of the brain that helps control motions. In people with this condition, the cerebellum protrudes through the hole at the base of the skull and into the spine. Symptoms may include headaches, neck pain and dizziness, and if too much of the brain bulges out, it can be fatal.
