Y Chromosome Microdeletion Marker
Overview
Y chromosome microdeletion markers refer to specific sequence-tagged sites (STS) on the azoospermia factor (AZF) regions of the long arm of the Y chromosome that are tested for deletions causing male infertility. These markers assess the presence of genes critical for spermatogenesis, particularly in the AZFa, AZFb, and AZFc regions. Deletions indicate severe oligozoospermia or azoospermia, while normal amplification patterns suggest intact testicular function. Clinically, Y microdeletion testing identifies genetic causes of non-obstructive azoospermia, informs intracytoplasmic sperm injection (ICSI) outcomes, and guides genetic counseling for male infertility.
Clinical Use Cases
- Evaluation of non-obstructive azoospermia or severe oligozoospermia.
- Pre-ICSI genetic screening to predict sperm retrieval success.
- Genetic counseling for infertile couples considering assisted reproduction.
- Assessment of testicular sperm extraction (TESE) candidates.
- Family studies to determine inheritance patterns.
Specimen Types
- Peripheral blood (EDTA whole blood).
- Buccal swab (less common).
- Fresh or frozen semen (DNA extraction).
Measurement Methods
- Multiplex polymerase chain reaction (PCR) for 20-30 STS markers.
- Sequence-tagged site (STS) analysis per EAA/ESRR guidelines.
- Quantitative fluorescent PCR for homogeneous deletions.
- Array comparative genomic hybridization (aCGH) for larger deletions.
- Next-generation sequencing for comprehensive Y chromosome analysis.
Test Preparation and Influencing Factors
- No fasting or special preparation required.
- Recent testosterone therapy may affect semen parameters but not DNA results.
- Blood collection in EDTA tubes; avoid heparin.
- Mosaic Y chromosome deletions may yield false negatives.
- Sample contamination or poor DNA quality affects PCR amplification.
- Population-specific deletion frequencies vary.
Synonyms
- AZF deletion testing.
- Yq microdeletion analysis.
- SRY-negative male infertility panel.