Arnold Chiari malformation (ACM) is a congenital condition that affects the bottom part of the brain and the spinal cord. It is a complex neurological disorder that is caused when a part of the brain, called the cerebellar tonsils, protrudes into the spinal canal at the base of the skull.
The exact cause of Arnold Chiari is unknown, but research suggests that there is a genetic component involved. While the exact mechanism is still unclear, studies suggest that it may be caused by a combination of genetic and environmental factors.
It is believed that the genetic component of Arnold Chiari is autosomal dominant, meaning that if one parent has the condition, there is a 50% chance that the child will also have the condition. Genetic testing and family history can help to determine the likelihood of ACM in a particular family.
In addition to genetic factors, environmental factors such as maternal alcohol use, smoking, and prenatal exposure to certain medications have also been linked to ACM. Other potential risk factors include maternal age, birth weight, and weight gain during pregnancy.
Although ACM can be caused by a combination of genetic and environmental factors, it is important to note that the majority of cases are not hereditary. Therefore, it is important for individuals to understand their family history and their own risk factors for ACM, and to discuss any concerns with their doctor.