SRY DELETION, FISH

The SRY Deletion FISH (Fluorescence In Situ Hybridization) test is used to detect the presence or absence of the SRY gene, located on the Y chromosome. This gene is essential for male sex differentiation. The test is particularly relevant in cases of ambiguous genitalia, disorders of sex development (DSDs), and suspected Y chromosome microdeletions.

This test is crucial in evaluating disorders of sexual development. It helps determine genetic sex when there is discordance between physical appearance and chromosomal findings. It is also used in infertility evaluations, particularly in males with azoospermia or severe oligospermia.

A blood or tissue sample is collected and treated with fluorescent probes that specifically bind to the SRY gene region on the Y chromosome. Under a fluorescent microscope, the presence or absence of the fluorescent signal indicates whether the SRY gene is present.

A positive result (presence of the SRY gene) confirms the existence of the gene and typically supports a male genotype. A negative result (absence of the SRY gene) may explain certain intersex conditions and helps in diagnosing DSDs. The results are interpreted alongside clinical findings and other genetic tests.

No special preparation is required for the patient. The test requires a proper sample and must be processed in a specialized cytogenetics laboratory.