Which chromosome abnormality is linked to DiGeorge syndrome?

Which chromosome abnormality is linked to DiGeorge syndrome?

• A. Defect on chromosome 22 with immunodeficiency, structural abnormalities, possible heart defects and cleft palate
• B. Trisomy 21
• C. Trisomy 18
• D. Turner syndrome

Answer: (A)

DiGeorge syndrome is tied to a deletion on chromosome 22, specifically 22q11.2, which disrupts development of the thymus and parathyroid glands. This leads to immunodeficiency from thymic hypoplasia (reduced T-cell production), and often hypocalcemia from parathyroid aplasia, along with common congenital heart defects and palate abnormalities like cleft palate. The option describing a defect on chromosome 22 with immunodeficiency, structural abnormalities, possible heart defects and cleft palate captures this characteristic pattern. Other chromosomal disorders involve different abnormalities and present with distinct features (for example, Down syndrome with Trisomy 21, Edwards syndrome with Trisomy 18, Turner syndrome with monosomy X), so they are not linked to DiGeorge syndrome.

DiGeorge syndrome is tied to a deletion on chromosome 22, specifically 22q11.2, which disrupts development of the thymus and parathyroid glands. This leads to immunodeficiency from thymic hypoplasia (reduced T-cell production), and often hypocalcemia from parathyroid aplasia, along with common congenital heart defects and palate abnormalities like cleft palate. The option describing a defect on chromosome 22 with immunodeficiency, structural abnormalities, possible heart defects and cleft palate captures this characteristic pattern. Other chromosomal disorders involve different abnormalities and present with distinct features (for example, Down syndrome with Trisomy 21, Edwards syndrome with Trisomy 18, Turner syndrome with monosomy X), so they are not linked to DiGeorge syndrome.