National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Split spinal cord malformation


Other Names:
Diastematomyelia; SSCM; Diplomyelia; Diastematomyelia; SSCM; Diplomyelia; Pseudodiplomyelia; Dimyelia; Split cord malformation; SCM type 1; Split cord malformation type 1 See More
Categories:
Split spinal cord malformation (SSCM) is a rare form of spinal dysraphism in which a person is born with splitting, or duplication, of the spinal cord. It may be characterized by complete or incomplete division of the spinal cord, resulting in two 'hemicords.' There are two types of SSCM. In type I, each hemicord has a full protective covering (thecal sac) and they are separated by a bony structure, forming a double spinal canal. In type II, the two hemicords are surrounded by one thecal sac and there is a single spinal canal. While SSCM is present from birth, it may become apparent at any age and is more common in women than in men. Some people may not have symptoms, while others may have a tethered cord and/or various other spinal abnormalities. Symptoms vary and may include back pain, bladder dysfunction, and leg pain or weakness. SSCM is thought to be caused by abnormal formation of the notochord and neural tube (which ultimately form the brain and spinal cord) very early in embryonic development.[1][2] Treatment may include surgery for release of a tethered cord, and/or physical therapy for neurologic problems or pain.[2]
Last updated: 12/7/2015

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Diastomatomyelia 0100563
30%-79% of people have these symptoms
Generalized hirsutism
Excessive hairiness over body
0002230
Scoliosis 0002650
Percent of people who have these symptoms is not available through HPO
Abnormality of the nervous system
Neurologic abnormalities
Neurological abnormality
[ more ] 		0000707
Autosomal recessive inheritance 0000007
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Last updated: 7/1/2020
Most cases of split spinal cord malformation (SSCM) appear to be isolated (occurring in one person in a family).[3] 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.[4] 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.[3]

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%.[5] 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.
Last updated: 12/7/2015

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Split spinal cord malformation. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • What is the heredity of split cord malformation? My husband has it, but it was not in the family before. He was told his mother was taking antibiotics during pregnancy and it could be a possible cause. What is the chance our baby will have it too? Is there any risk, and if there is, how big is it? How can we plan for a pregnancy and what preventive actions can we take? See answer


  1. Chaouki Khoury. Closed spinal dysraphism: Pathogenesis and types. UpToDate. Waltham, MA: UpToDate; November, 2015;
  2. Chaouki Khoury. Closed spinal dysraphism: Clinical manifestations, diagnosis, and management. UpToDate. Waltham, MA: UpToDate; November, 2015;
  3. Victor A. McKusick, Sonja A. Rasmussen. DIASTEMATOMYELIA. OMIM. October 5, 1999; http://www.omim.org/entry/222500.
  4. Ersahin Y, Kitis O, Oner K. Split cord malformation in two sisters. Pediatr Neurosurg. November, 2002; 37(5):240-244.
  5. Peter S. Harper. Central nervous system disorders. Practical Genetic Counselling. London: Arnold; 2003; 176.