What are the causes and symptoms of spina bifida?
Spina bifida may occur as an isolated abnormality or in the company of other malformations. As an isolated abnormality, spina bifida is caused by the combination of genetic factors and environmental influences that bring about malformation of the spine and spinal column. The specific genes and environmental influences that contribute to the many-factored causes of spina bifida are not completely known. An insufficiency of folic acid is known to be one influential nutritional factor. Changes (mutations) in genes involving the metabolism of folic acid are believed to be significant genetic risk factors. The recurrence risk after the birth of an infant with isolated spina bifida is 3–5%. Recurrence may be for spina bifida or another type of spinal abnormality. Spina bifida may arise because of chromosome abnormalities, single gene mutations, or specific environmental insults such as maternal diabetes mellitus or prenatal exposure to certain anticonvulsant drugs. The recurrence risk varies
