The majority of cardiac malformations (30%) are ventricular septal defects, an abnormal communication between the left and right ventricles [3].
Identification of causative factors is confounded by the fact that the majority of these malformations appear to result from a combination of genetic and environmental factors.
Although the phenotypes were too varied to identify the molecular and cellular causes of each phenotype, the cell death that is distributed throughout regions of the neuroepithelium around the time of neural crest generation might explain a majority of the malformations observed here.
As all malformation-related death causes were excluded from the study, the majority of these undetected malformations would probably not be related to infant mortality.
While the overwhelming majority of congenital heart malformations do not segregate in Mendelian ratios, they do show familial aggregation, which suggests that genetic factors play a role in their development [ 2, 3].
The majority of the defects were malformations of the septum with 30.6% atrial septal defect (ASD, Figure 2B) and 40.3% ventricular septal defect (VSD, Figure 2C).
In a study on the long-term outcome of anorectal malformations, the majority of patients/children had behavioural problems and 15% expressed suicidal thoughts, though more than half scored above average on a global hopefulness scale [ 17].
There was no increased risk of malformations in general, major malformations or cardiac malformations among the women who had used cranberry during early pregnancy.
Although some underlying causes of epilepsy are readily identified (e.g., brain tumour, cortical malformation), the majority of cases of epilepsy have no known cause [1].
Suboccipital craniectomy, whether or not combined with a C1-C3 laminectomy, relieves cough headache in the majority of patients with a Chiari malformation type I [11, 13].
