Table IV.

Associated central nervous system malformations in 317 infants with agenesis of the corpus callosum diagnosed by magnetic resonance imaging at < 1 year of age from a population of over 3 million live births in California from 1983 to 2003.

	Chromosomal N = 36		Non-Chromosomal N = 281
N (%)
None	22	(61.1)	138	(49.1)
Cortical Malformation	7	(19.4)	79	(28.1)
Posterior fossa abnormality
Cerebellar vermis or hemisphere	3	(8.3)	31	(11.0)
Chiari malformation	0	(0)	5	(1.8)
Brainstem abnormality	1	(2.8)	9	(3.2)
Encephalocele	1	(2.8)	3	(1.1)
Spinal cord abnormality	0	(0)	5	(1.8)