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Y chromosome microdeletions

General aspects

Formation and maturation of spermatozoa (spermatogenesis) is a complex process that takes place under the control of different genes, located in a specific region of the long arm of the Y chromosome named AZF (AZoospermia Factor AZF). This region is divided into three subregions defined AZFa, AZFb, AZFc, and includes the genes involved in spermatogenesis. The microdeletion, a loss of one or more subregions not visible with a karyotype, is associated with a male infertility and it represents the most frequent cause of non-obstructive/oligo azoospermia (10-15% of cases). The most common microdeletion includes the AZFc region (60-80% of cases), followed by AZFb (9-16%)region and AZFa (3-5%); rarely it can miss two regions (AZFbc) or all three (AZFabc).

Fig.1 - Rappresentazione schematica di microdelezione del cromosoma Y.

Fig.1 - Scheme of Y chromosome microdeletions
Genetic test

The test consists in a PCR amplification of specific sequences, named STS (Sequence-tagged site), located in three AZF subregions of Y-chromosome. The STS analyzed are sY84 and sY86 for the AZFa subregion, sY127 and sY134 for the AZFb subregion, sY254 and sY255 for the AZFc subregion. The amplification products are then analyzed by electrophoresis on agarose gel.

Genetic counseling

Tecnobios Eurogenlab Prenatal gives a genetic counseling service to inform patients and parents, in a clear terms about the disease, diagnosis and treatments.

Response times

The result is generally available after 10 days from draw blood.

Analyzed material

DNA is extracted from peripheral blood, collected in tubes with EDTA.

Sources sites
http://www.sidr.it/
http://www.orpha.net