atrioventricular (AV) septal defect; endocardial cushion defect (AVSD)

Pathology

• spectrum of cardiac malformations that result in a persistent common atrioventricular canal
• the complete form involves underdevelopment of the lower part of the atrial septum & the upper part of the ventricular septum
• a less severe form, known as partial AVSD or ostium primum atrial septal defect has a deficiency of the atrial septum

Genetics

• associated with defects in HEY2 gene (AVSD)
• associated with defects in CRELD1 gene (AVSD2)
• associated with defects in GATA4

Clinical manifestations

• complete AVSD are clinically apparent at birth
• less severe forms, such as an isolated cleft mitral valve or small defects of the atrial or ventricular septa may go undetected

More general terms

• cardiac septal defect

Database

• OMIM: https://mirror.omim.org/entry/600309
• OMIM: https://mirror.omim.org/entry/606217
• OMIM: https://mirror.omim.org/entry/614430