AZFb microdeletions and oligozoospermia--which mechanisms?
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.


METHODS
Case report.


METHODS
Genetics Department of Faculty of Medicine of Porto, Porto, Portugal.


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


METHODS
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.


METHODS
Study of the fine structure of the Y-chromosome and discussion of the putative mechanisms involved in each microdeletion pattern.


RESULTS
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.


CONCLUSIONS
Analysis of these patients has revealed a new putative region that may be involved in spermatogenesis conservation.
Genetics Department, Faculty of Medicine, University of Porto, Porto, Portugal.
Ana Rita
AR
Soares
Paula
P
Costa
Joaquina
J
Silva
Mário
M
Sousa
Alberto
A
Barros
Susana
S
Fernandes
D000328:Adult; D056905:Chromosome Breakpoints; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics; D005298:Fertility / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D007248:Infertility, Male; D007621:Karyotyping; D008297:Male; D008875:Middle Aged; D009845:Oligospermia / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy; D010641:Phenotype; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D027724:Reproductive Techniques, Assisted; D016324:Sequence Tagged Sites; D012720:Severity of Illness Index; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy; D013091:Spermatogenesis / Q000235:genetics*; D016896:Treatment Outcome