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

References

OMIM :accession 600309, 606217