Which genetic condition is most commonly associated with an atrioventricular canal in infants?

The genetic condition most commonly associated with an atrioventricular canal defect in infants is Trisomy 21, also known as Down syndrome. This condition is characterized by the presence of an extra copy of chromosome 21, leading to a range of developmental and physical challenges.

Atrioventricular canal defects occur due to improper formation of the heart structures during early fetal development. In infants with Trisomy 21, these defects are observed more frequently compared to other genetic syndromes. The link between Trisomy 21 and heart defects, including atrioventricular canal, has been well-established through clinical studies, highlighting that about 40-50% of infants with Down syndrome may exhibit congenital heart defects, with atrioventricular canal being one of the prominent types.

The other genetic conditions listed do have associations with congenital heart defects but do not share the same strong prevalence or specific link to atrioventricular canal defects as seen in Trisomy 21. Therefore, the prevalence and the specific connection of atrioventricular canal defects with Trisomy 21 make it the most accurate answer in this context.