Aids in determining the cause of azoospermia or oligospermia and helps predict effectiveness of assisted reproductive technologies in men with Y chromosome microdeletions.
- Patient Preparation
- Lavender (EDTA) or pink (K2EDTA). Also acceptable: Yellow (ACD Solution A or B), lt. blue (sodium citrate), green (sodium or lithium heparin).
- Specimen Preparation
- Do not freeze. Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Serum. Frozen specimens. Severely hemolyzed specimens.
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Y chromosome microdeletions are typically characterized by azoospermia, severe to moderate oligospermia, or abnormal sperm morphology/motility in men with a normal physical evaluation. Assisted reproductive techniques are contraindicated for men carrying AZFa, AZFb, AZFbc or AZFabc microdeletions, which are classically associated with spermatogenic failure.
Prevalence: 1 in 2,000 to 3,000 males carry Y chromosome deletions/microdeletions.
Penetrance: Approaches 100 percent in males; variable expression may result in intra-familial variation of fertility in men with an identical microdeletion.
Inheritance: Y-linked; microdeletions are typically de novo.
Cause: Microdeletions of the Y chromosome azoospermia factor regions a, b or c (AZFa, AZFb or AZFc).
Mutations Tested: Five common Y chromosome microdeletions: AZFa, AZFb, AZFc, AZFbc, and AZFabc.
Clinical Sensitivity: Estimated at 5 to 10 percent for men with non-obstructive azoospermia or severe oligospermia.
Methodology: Multiplex polymerase chain reaction (PCR) followed by electrophoresis.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations:Diagnostic errors can occur due to rare sequence variations. Mutations within individual genes included in the AZF regions will not be detected. Breakpoints of identified microdeletions will not be determined. Male infertility due to causes other than Y chromosome microdeletions tested, has not been excluded.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2001779||Y CHROM Specimen||31208-2|
|2001781||Y Chromosome Result||35456-3|