What is Sacral Agenesis?

Sacral agenesis is a rare and little-known condition that causes deformity of the spine. This condition occurs in only about one in every 25,000 live births. Researchers believe that this abnormality occurs at some point between weeks three and seven of fetal development due to a factor or set of factors which interrupt the mesoderm migration.

Those who are born with sacral agenesis may suffer from small lesions on the lower spine or more serious effects, including fusion of the lower limbs. Although it is unknown why exactly this occurs, it is speculated that a lack of certain vital nutrients during pregnancy may be a factor. For example, folic acid taken in sufficient amounts may help prevent this and other spinal defects in newborns.

The links between sacral agenesis and lack of nutrients, along with other environmental factors, is weak at best. Some indicators point to maternal diabetes as a possible risk factor, but no specific environmental cause has been linked conclusively. Most cases of sacral agenesis are caused by hereditary factors. Inherited causes, also called Currarino syndrome, are believed to be caused by the mutation of certain genes.

There are four main types of sacral agenesis, some more severe than others. The first involves the partial formation of the sacrum. This means that some of the lower back is developed, but certain components are missing. Another type is the deformation of the sacrum, and the two additional types involve the total failure of sacrum formation.

Because there are varying degrees of severity in sacrum agenesis, the prognosis is equally varied. Some children may go on to live ordinary lives with surgery combined with physical therapy. Others may have fully malformed legs and hips, making walking or even crawling impossible. These children will likely be confined to a wheelchair. Sometimes the lower limbs are even removed.

In some very severe cases, bladder and bowel function are inhibited. This may necessitate the use of permanent colostomy to prevent bowel incontinence as well as catheterization for urine passage. Despite these limitations, the prognosis is improving for these patients as more efficient surgeries and physical therapies are developed; along with more technologically advanced wheelchairs and mobility aids.

To prevent sacral agenesis from occurring, all women in their childbearing years are encouraged to take a daily multivitamin that contains folic acid. Maintaining a healthy diet and lifestyle is also beneficial by preventing the onset of type two diabetes. Quality prenatal care is also important so care providers can spot any abnormalities, and treatment options can be made available the moment of birth.