New insights into the development of the closed spinal dysraphism, terminal myelocystocele

A team of researchers led by Dr. Gabriel Galea at University College London (UCL) have published a new study of how terminal myelocystocele (TMC) develops. TMC is a rare, closed spinal dysraphism related to spina bifida. In TMC a skin-covered sac/cyst, containing cerebrospinal fluid and nerve tissue, protrudes through a defect towards the end (terminus) of the spine and the cord becomes abnormally flattened.

The early stages of spinal cord development in humans are completed in the first 30 days of pregnancy. Such early human embryos are difficult to access for research so mice are commonly used to study spinal cord development instead. In the study published in the journal Development, the UCL researchers showed a striking similarity in the ways the spinal cord developed in humans and mice. They had previously identified anatomical structures which help cover the spinal cord with skin in mice, but these had never been seen in humans. By using over a decade's worth of human embryo images collected by the Human Developmental Biology Resource, the researchers found examples that suggest that same structure also forms in humans.

By studying mouse models, the researchers were able to find a process inside the mouse cells that led to the spinal structure developing. When they then blocked this process, the mice developed TMC.

The UCL researchers showed that TMC occurs slightly later in embryo development than open spina bifida and via a distinct mechanism. The findings provide new insights into the causes of TMC and raise questions for future research, including the possible role of folate in the process and the effect of folic acid.

Read study of how terminal myelocystocele (TMC) develops