DiGeorge syndrome - 22q11deletion - FISH

DiGeorge syndrome. Human chromosomes stained with fluorescent probes (fluorescence in situ hybridisation or FISH). The probes bind to specific sequences of DNA. There has been a deletion in chromosome 22. A control probe marks the telomeres of both 22 homologues. A probe from the Tuple 1 region of the DiGeorge Syndrome Critical Region (DGSCR) marks the hemizygous deletion in 22a11. The syndrome is due to the absence of the thymus and parathyroid glands, resulting in impaired immunity, short stature, and deformities of the face, heart and great vessels. Also called thymic- parathyroid aplasia. Image by Dr John Crolla.