Objectives: To evaluate prenatal imaging diagnosis of agenesis of corpus callosum and to investigate the relationship between ACC and chromosomal abnormalities.
Methods: Forty singleton pregnancies diagnosed ACC prenatally in Southern Medical University,Nanfang Hospital,General Hospital of Guangzhou Military Command of PLA and Shenzhen Maternity and Children Health Care Hospital from 2007 to 2012 were recruited. The correlation between ACC and chromosomal abnormalities, the consistence of sonographic characteristics and MRI diagnosis were analyzed retrospectively.
Results: (1) Among the 40 cases, 15 (38%, 15/40) were diagnosed isolated ACC, while 25 (63%, 25/40) were non-isolated ACC.In the non-isolated ACC cases, 18 (72%) had central nervous system abnormalities, including cerebellar vermis hypoplasia,Dandy-Walker syndrome, cerebellar cyst, holoprosencephaly, etc.Extra-CNS abnormalities were identified in 16 cases, including 5 cardiac abnormalities, 3 facial abnormalities, 2 congenital anomalies of urinary system, 1 limb skeletal abnormality and 5 other congenital anomalies.(2) In the 40 cases, 3 were chromosomal polymorphisms, including 2 cases of 46,XX, 1qh+ and 1 case of 46,XY, 13cenh+. Chromosomal abnormalities were identified in 4 cases, including trisomy13, trisomy18, trisomy 21 and 47,XYY.(3) 36 cases(90%, 36/40) diagnosed by ultrasound were consistent with MRI, while 4 cases were different with MRI.37 pregnancies were terminated, in which 28 cases were confirmed by fetal autopsy.3 cases continued pregnancy and ACC was confirmed by postnatal MRI.(4) 25 non-isolated ACC and 12 isolated ACC pregnancies were terminated. Among the 3 isolated ACC cases that continued pregnancy, 2 were term delivery and 1 was premature delivery. All of them were confirmed by postnatal MRI.No mental or growth retardation was found during follow-up.
Conclusion: MRI was prior to detect cases with non-isolated ACC and could be a supplementary method in the diagnosis and classification of ACC. Compared with isolated ACC, non-isolated ACC had a higher incidence of chromosomal abnormalities.