Which of the following statement concerning spina bifida is True?

Spina bifida approximately 20% of affected infants have additional congenital abnormalities. Chromosomal abnormalities, single-gene mutations, and teratogenic causes can be identified in < 10% of affected children. Myelomeningocele is the most common type of spina bifida and is characterized by herniation of the spinal cord, nerves, or both through a bony defect of the spine. Spina bifida occult is the mildest form of spina bifida. It occurs most often in S 1, S2, or both and is characterized by a bony defect of the spine that is usually covered by normal skin. A meningocele, a third type of spina bifida, is a saccular herniation of meninges and CSF through a bony defect in the spine. Spina bifida occurs more commonly in whites. Recent data suggest that infants of women who consume at least 400mg of folic acid daily during pregnancy have a decreased incidence of neural-tube defects. Reference: GHAI Essential pediatrics, 8th edition