Which syndrome is characterized by congenital heart disease, immunodeficiency, and hypoparathyroidism and is associated with deletion on chromosome 22?

• A. Down syndrome
• B. DiGeorge syndrome
• C. Klinefelter syndrome
• D. Turner syndrome

Answer: (B)

The triad of congenital heart disease, immune deficiency, and hypoparathyroidism points to DiGeorge syndrome. This condition results from a deletion on chromosome 22, most often 22q11.2, which disrupts the development of the third and fourth pharyngeal pouches. That disruption leads to thymic hypoplasia or aplasia (causing T-cell immunodeficiency) and underdeveloped parathyroids (causing hypoparathyroidism and related low calcium risks). Cardiac defects are common, especially conotruncal types like tetralogy of Fallot or truncus arteriosus, reflecting the same developmental disruption. Other syndromes listed don’t feature this specific combination of immune deficiency, parathyroid failure, and a chromosome 22 deletion, so they don’t fit the presentation as well.