Split spinal cord malformation

Most cases of split spinal cord malformation (SSCM) appear to be isolated (occurring in one person in a family).^[1] To our knowledge, only 4 reports in the medical literature describe familial cases of SSCM. All reports of familial cases describe affected siblings, and all have been female.^[2] We are not aware of any reports describing an affected parent and child.

Due to the rarity of reports of SSCM, there may be limited data to determine if, and how, SSCM may be inherited. In one report, the authors suggested it may be inherited in an X-linked dominant manner, or it may be a multifactorial condition (caused by a combination of genetic and environmental factors) with female sex preference.^[1]

People with spinal dysraphism with a significant spinal defect reportedly show an increased incidence of open neural tube defects (ONTDs) in their children. The risk is thought to be similar to that for open spina bifida, which is about 4%.^[3] However, because no genetic cause of SSCM has been identified and there is no clear inheritance pattern, we cannot estimate the exact chance that a person will have a child with SSCM.

A parent with a severe form spinal dysraphism is encouraged to speak with their prenatal care provider regarding the option of prenatal testing for ONTDs.

People with specific questions about their family history and recurrence risks are encouraged to speak with a genetics professional.

We are not aware of risk factors during pregnancy known to be associated with split spinal cord malformation (SSCM) specifically. There also doesn't appear to be a unified risk factor for all types of closed spinal dysraphism (which includes SSCM).^[4]

Folic acid deficiency has been clearly associated with open spinal dysraphism, but no studies have addressed whether there is a relationship between folic acid deficiency and closed spinal dysraphism. Likewise, maternal exposure to certain medications (anticonvulsant drugs) has been associated with spinal dysraphism in the fetus, but human studies have generally focused on open, rather than closed, spinal dysraphism.^[4]

We are not aware of evidence that maternal exposure to antibiotics is associated with SSCM.

Studies regarding risk factors for spinal dysraphism (which includes SSCM) have primarily focused on open spinal dysraphism. Folic acid deficiency has been clearly associated with open spinal dysraphism, but no studies have addressed whether there is a relationship between folic acid deficiency and closed spinal dysraphism.^[4] We are not aware of information about preventing SSCM and other types of closed spinal dysraphism.^[4]

People with spinal dysraphism with a significant spinal defect reportedly show an increased incidence of open neural tube defects (ONTDs) in their children.^[3] Generally, women who may have an increased risk to have a child with a neural tube defect are advised to take a higher dose of folic acid before and during the first three months of pregnancy.

People with a family history of SSCM or any other birth defect are encouraged to speak with a genetic counselor or other genetics professional.

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.