What chromosomal abnormalities are associated with Tetralogy of Fallot (TOF)?

Tetralogy of Fallot (TOF) is a congenital heart defect that is often associated with specific chromosomal abnormalities. Among these, the deletion on chromosome 22, known as 22q11.2 deletion syndrome (also referred to as DiGeorge syndrome), is one of the most significant. This deletion is associated with various health issues, including heart defects like TOF. The presence of this chromosomal abnormality is strongly linked to the development of TOF and is seen in a notable percentage of patients with this condition.

The association of TOF with chromosome 21 (which pertains to Down syndrome, also known as Trisomy 21) is not as pronounced. Although some cardiac defects are prevalent in individuals with Down syndrome, they typically involve different types of cardiac conditions than the specific anatomical defects seen in TOF.

In contrast, other chromosomal abnormalities such as those related to chromosomes 18 (Trisomy 18) or 20 do not show the same strong correlation with TOF as the deletion on chromosome 22. Hence, the link between the 22q deletion and TOF makes it the correct choice in this context.