AZFb microdeletions and oligozoospermia—which mechanisms?

Capsule:
Atypical deletion patterns are presented in two oligozoospermic males. The Y chromosome with highly repetitive block sequences in AZFb and AZFc led to deletions by intrachromosomal recombination mechanisms (28w).

Authors:
Ana Rita Soares, M.D., Paula Costa, M.Sc., Joaquina Silva, M.D., Mário Sousa, M.D., Ph.D., Alberto Barros, M.D., Ph.D., Susana Fernandes, Ph.D.
Volume 97, Issue 4 , Pages 858-863, April 2012

Objective:
To characterize the deletion patterns and its breakpoints in oligozoospermic patients presenting AZFb and AZFc microdeletions and to understand the recombination mechanisms underlying these microdeletions.

Design:
Case report.

Setting:
Genetics Department of Faculty of Medicine of Porto, Porto, Portugal.

Patient(s):
Two men with severe oligozoospermia and two men with nonobstructive azoospermia identified as having different AZFb+c deletion patterns via Y chromosome microdeletion analysis.

Intervention(s):
Definition of microdeletions and the fine characterization of the respective breakpoints by sequence-tagged sites (STS) polymerase chain reaction (PCR) and single-nucleotide variant (SNV) PCR.

Main Outcome Measure(s):
Study of the fine structure of the Y-chromosome and discussion of the putative mechanisms involved in each microdeletion pattern.

Result(s):
From the four patients studied, three deletion patterns were identified: IR4/distal-P2 (25%; 1 of 4), P5/proximal-P1 (50%; 2 of 4), and P5/distal-P1 (25%; 1 of 4). Although severe oligozoospermia is normally associated with AZFc, a complete AZFb deletion was found in one case.

Conclusion(s):
Analysis of these patients has revealed a new putative region that may be involved in spermatogenesis conservation.

Translate »