Uniform deletion junctions of complete azoospermia factor region c deletion in infertile men in Taiwan

High frequency of TTTY2-like gene-related deletions in patients with idiopathic oligozoospermia and azoospermia

Genes located on Y chromosome and expressed in testis are likely to be involved in spermatogenesis. TTTY2 is a Y-linked multicopy gene family of unknown function that includes TTTY2L2A and TTTY2L12A at Yq11 and Yp11 loci respectively. Using PCR amplification, we screened for TTTY2L2A- and TTTY2L12A-associated deletions, in 94 Greek men with fertility problems. Patients were divided into three groups as following: group A (n = 28) included men with idiopathic moderate oligozoospermia, group B (n = 34) with idiopathic severe oligozoospermia and azoospermia, and group C (n = 32) with oligo- and azoospermia of various known etiologies. No deletions were detected in group C patients and 50 fertile controls. However, two patients from group A had deletions in TTTY2L2A (7.1%) and six in TTTY2L12A (21.4%), whereas from group B, four patients had deletions in TTTY2L2A (11.8%) and 10 in TTTY2L12A (29.4%). In addition, five patients from both groups A and B (8%) appeared to have deletions in both studied TTTY2 genes, although these are located very far apart. These results indicate that the TTTY2 gene family may play a significant role in spermatogenesis and suggest a possible mechanism of nonhomologous recombinational events that may cause genomic instability and ultimately lead to male infertility.

A simplified gene-specific screen for Y chromosome deletions in infertile men

OBJECTIVE

To test the diagnostic efficiency of a gene-specific, five-marker screening strategy for the detection of Y chromosome deletions.

DESIGN

Prospective case study.

SETTING

University genetics laboratory and reproductive clinics.

PATIENT(S)

Six hundred twenty-seven infertile men and 212 fertile men.

INTERVENTION(S)

Peripheral blood samples were screened for Y chromosome deletions in a triple-blind fashion using three protocols: protocol I consisted of five gene-specific markers, including USP9Y, DBY, SMCY, RBM1, and DAZ; protocol II included 14 gene-specific markers; and protocol III consisted of six sequence-tagged sites (STSs) markers recommended by EAA/EMQN.

MAIN OUTCOME MEASURE(S)

Deletion status of Y chromosome genes or sequence-tagged sites.

RESULT(S)

Protocols I and II identified the same 41 infertile patients with Y deletions. Protocol III identified 38 infertile patients with Y deletions, and all 38 patients were also identified by protocols I and II. One patient with isolated USP9Y deletion and two patients with isolated DBY deletions, as detected by protocols I and II, could not be identified by protocol III.

CONCLUSION(S)

We observed mostly consistent results between our protocols and the EAA/EMQN protocol. This gene-specific, five-marker screening panel provides the same diagnostic efficiency as the EAA/EMQN protocol and may be considered an alternative to the EAA/EMQN protocol.