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Interpretive Handbook

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Test 88537:
Sex-Determining Region Y, Yp11.3 Deletion, FISH

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The SRY (sex-determining region on the Y chromosome) gene is required for normal embryonic wolffian (male) genital development, although numerous other genes are involved in completing the process of normal male development. Some gene mutations block the action of SRY in development. Thus, a 46,XY individual with an SRY deletion or mutation will develop as a female, and a 46,XX individual with translocation of SRY to 1 X chromosome will develop as a male. Structural abnormalities of the Y chromosome result in a spectrum of abnormalities from primary infertility (male or female) to various forms of ambiguous genitalia. SRY-negative 46,XX males often have ambiguous genitalia, whereas those who are positive for SRY usually have a normal male phenotype with azoospermia. SRY-negative 46,XY females may have another mutation, such as 1 involving the SOX9 gene.

 

We recommend conventional chromosome studies (CMS/8696 Chromosome Analysis, for Congenital Disorders, Blood) to detect Y chromosome abnormalities and to rule out other chromosome abnormalities or translocations, and FISH studies to detect cryptic translocations involving the SRY region that are not demonstrated by conventional chromosome studies.

Useful For Suggests clinical disorders or settings where the test may be helpful

Aiding in the detection of the SRY gene in males with primary infertility, XY females, and individuals with ambiguous genitalia, in conjunction with conventional chromosome studies (CMS/8696 Chromosome Analysis, for Congenital Disorders, Blood)

Interpretation Provides information to assist in interpretation of the test results

Any male individual with an SRY signal on a structurally normal Y chromosome is considered negative for a deletion in the region tested by this probe. Any patient with a FISH signal pattern indicating loss of the critical region will be reported as having a deletion of the regions tested by this probe. Any patient with a FISH signal on an X chromosome will be reported as having a cryptic X;Y translocation involving the critical region.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This FISH test is not approved by the FDA.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

1. Margarit E, Coll MD, Oliva R, et al: SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite. Am J Med Genet 2000 Jan;90(1):25-28

2. Lopez M, Torres L, Mendez JP, et al: SRY alone can induce normal male sexual differentiation. Am J Med Genet 1995 Jan;55(3):356-358