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Mayo Test ID YMCRO Y Chromosome Microdeletions, Molecular Detection, Varies


Shipping Instructions


 



Specimen Required


Patient Preparation: A previous bone marrow transplant from an allogeneic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.

Specimen Type: Whole blood

Container/Tube: 

Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: None

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

Additional Information:

1. Specimens are preferred to be received within 4 days of collection. Extraction will be attempted for specimens received after 4 days, and DNA yield will be evaluated to determine if testing may proceed.

2. To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.


Useful For

Evaluating men with azoospermia, severe oligozoospermia, or otherwise unexplained male factor infertility

Method Name

Polymerase Chain Reaction (PCR)

Reporting Name

Y Microdeletion

Specimen Type

Varies

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Frozen 
  Refrigerated 

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Yq microdeletions involving some or all azoospermic factor (AZF) regions, are identified in approximately 3% of infertile men. Yq microdeletions are also the most frequently identified cause of spermatogenic failure in chromosomally normal men with nonobstructive azoospermia (3%-15%) or severe oligospermia (6%-10%). The relative frequency of Yq microdeletions makes the evaluation for them an important aspect of the diagnostic work up in infertile men, especially those with azoospermia or severe oligospermia.

 

Most cases of Yq microdeletions occur de novo, and due to the consequential infertile phenotype, they are typically not transmitted. However, in cases where assisted reproductive technology (eg, testicular sperm extraction followed by intracytoplasmic sperm injection) is used to achieve viable pregnancy, all male offspring born to a microdeletion carrier will carry the deletion and may be infertile.

 

Men testing positive for 1 or more microdeletions who are enrolled in an in vitro fertilization treatment program may wish to consider alternative options to intracytoplasmic sperm injection (eg, donor sperm), and consultation with an experienced reproductive endocrinologist and medical geneticist is recommended.

 

Most Y microdeletions are the result of homologous recombination between repeated sequence blocks. Testing for deletions involves investigating for the presence or absence of markers located within nonpolymorphic regions of the AZF region.

Interpretation

The interpretive report includes an overview of the findings as well as the associated clinical significance.

Cautions

This assay will not detect all causes of infertility or azoospermia. Therefore, the absence of a detectable microdeletion does not rule out the presence of other genetic or nongenetic factors that may be the cause of clinical findings.

 

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in the interpretation of results may occur if information given is inaccurate or incomplete.

 

Rare variants (ie, polymorphisms) exist that could lead to false-negative or false-positive results. If results obtained do not match the clinical findings, additional testing should be considered.

 

In rare cases, DNA alterations of undetermined significance may be identified.

 

A genetic consultation is recommended for all patients undergoing this testing. Additional consultation with a reproductive endocrinologist/urologist to discuss reproductive options is recommended when a deletion is detected.

Clinical Reference

1. Stahl PJ, Masson P, Mielnik A, Marean MB, Schlegel PN, Paduch DA. A decade of experience emphasizes that testing for Y microdeletions is essential in American men with azoospermia and severe oligozoospermia. Fertil Steril. 2010;94(5):1753-1756

2. Bhasin S. Approach to the infertile man. J Clin Endocrinol Metab. 2007;92(6):1995-2004

3. Fan Y, Silber SJ. Y Chromosome Infertility. In: Adam MP, Feldman J, Mirzaa GM, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2002. Updated August 1, 2019. Accessed November 18, 2024. Available at www.ncbi.nlm.nih.gov/books/NBK1339/

4. Kim SY, Kim HJ, Lee BY, Park SY, Lee HS, Seo JT. Y Chromosome Microdeletions in Infertile Men with Non-obstructive Azoospermia and Severe Oligozoospermia. J Reprod Infertil. 2017;18(3):307-315

Method Description

Multiplex polymerase chain reaction and agarose gel electrophoresis are used to test DNA for the presence of microdeletions in the AZFa, AZFb, and AZFc regions of the Y chromosome.(Simoni M, Bakker E, Krausz C. EAA/EMQN best practice guidelines for molecular diagnosis of y-chromosomal microdeletions. State of the art 2004. Int J Androl. 2004;27[4]:240-249)

Day(s) Performed

Wednesday

Report Available

7 to 10 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

81403-DAZ/SRY (deleted in azoospermia and sex determining region Y) (eg, male infertility), common deletions (eg, AZFa, AZFb, AZFc, AZFd)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
YMCRO Y Microdeletion 35456-3

 

Result ID Test Result Name Result LOINC Value
53364 Result Summary 50397-9
53365 Result 82939-0
53366 Interpretation 69047-9
53367 Specimen 31208-2
53368 Source 31208-2
53369 Released By 18771-6

Reference Values

An interpretive report will be provided.

Specimen Retention Time

Whole blood: 2 weeks (if available); Extracted DNA: 3 months