- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: TAS. (OMIM:614430)
- Primum atrial septal defect (HP:0010445): An ostium primum atrial septal defect is located in the most anterior and inferior aspect of the atrial septum. The ostium primum refers to an anterior and inferior opening (ostium) within the septum primum, which divides the rudimentary atrium during fetal development. The ostium primum is normally sealed by fusion of the superior and inferior endocardial cushions around 5 weeks' gestation. Ostium primum defects result from a failure of the fusion of the embryologic endocardial cushion and septum primum. Evidence: TAS. (OMIM:614430)
- Autosomal dominant inheritance (HP:0000006): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: TAS. (OMIM:614430)
These phenotypes are associated with the disease atrioventricular septal defect 4 (OMIM:614430).