Is Diastematomyelia Inherited?
Diastematomyelia (split spinal cord malformation) is not an inherited condition—it is a sporadic congenital malformation that occurs during embryonic development without a known genetic basis or familial pattern of transmission.
Nature of the Condition
Diastematomyelia is a rare form of spinal dysraphism characterized by a sagittal cleft in the spinal cord, where the cord is split longitudinally into two hemicords by an osseous, fibrocartilaginous, or fibrous septum 1, 2. This developmental anomaly occurs during early embryogenesis as a failure of normal neural tube formation 3.
Genetic and Inheritance Considerations
No hereditary pattern has been established for diastematomyelia in the medical literature 1, 2, 3.
Unlike conditions such as Klippel-Feil syndrome (which can have autosomal dominant inheritance patterns and may be associated with split cord malformations), diastematomyelia itself does not demonstrate familial clustering or genetic transmission 4.
The condition is considered a sporadic congenital malformation rather than an inherited disorder 1, 3.
There is no identified genetic mutation or chromosomal abnormality that causes diastematomyelia, distinguishing it from truly genetic conditions like dilated cardiomyopathy (which shows autosomal dominant inheritance in 30-50% of cases) 5.
Clinical Implications for Families
Family members of affected individuals are not at increased risk for having children with diastematomyelia 1, 2.
Genetic counseling is generally not indicated for diastematomyelia as an isolated finding, since there is no evidence of heritability 1, 3.
When diastematomyelia is discovered, the focus should be on evaluating for associated congenital anomalies (such as butterfly vertebrae, hemivertebrae, or other vertebral malformations) rather than investigating family history 5, 6.
Important Distinction from Associated Syndromes
While diastematomyelia itself is not inherited, it can occasionally occur as part of broader syndromic conditions that may have genetic components (such as Klippel-Feil syndrome) 4. However, in these cases, it is the underlying syndrome that is inherited, not the diastematomyelia specifically 4.
Prenatal Detection and Recurrence
Prenatal ultrasound can detect diastematomyelia as early as 13 weeks gestation, with most cases diagnosed around 19-21 weeks 1, 2.
Isolated diastematomyelia (without other spinal anomalies) has a favorable prognosis and does not indicate increased risk for future pregnancies 1, 2.
Normal amniotic fluid alpha-fetoprotein (AF-AFP) and acetylcholinesterase (AF-AChE) levels distinguish isolated diastematomyelia from open neural tube defects 1, 2.