title: Identification of new breakpoints in AZFb and AZFc.
abstract: Microdeletions in AZFa, AZFb and AZFc regions lead to different patterns of male infertility, from severe oligozoospermia to non-obstructive azoospermia. Intrachromosomal homologous recombination mechanisms were already identified in patients with simultaneous microdeletions in the AZFb and AZFc regions. Ten patients with atypical AZFb and AZFc deletion patterns were studied. The definition of those microdeletions and the fine characterization of the respective breakpoints were performed using sequence tagged sites/single nucleotide variants-PCR and DNA sequencing. Y-chromosome haplogroups were determined to establish a putative association with the patterns obtained. Seven deletion patterns were identified, P5/terminal (30%; 3/10), P5/P1 distal (20%; 2/10), IR4/distal-P2, IR2/proximal-P1, IR4/distal-P1, P4/terminal and complete AZFb/c deletion (10%; 1/10). Breakpoint sequence analysis suggests that only in one patient the P5/P1 distal deletion pattern was due to a homologous recombination mechanism. Sequence alignment of the other deletion patterns suggest that they have resulted from non-homologous recombination mechanisms.
authors.affiliation: Department of Genetics, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Costa
authors.forename: Rita
authors.initials: R
authors.lastname: Gonçalves
authors.forename: Cristina
authors.initials: C
authors.lastname: Ferrás
authors.forename: Susana
authors.initials: S
authors.lastname: Fernandes
authors.forename: Ana Teresa
authors.initials: AT
authors.lastname: Fernandes
authors.forename: Mário
authors.initials: M
authors.lastname: Sousa
authors.forename: Alberto
authors.initials: A
authors.lastname: Barros
mesh_terms: D000328:Adult; D001483:Base Sequence; D019457:Chromosome Breakage; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D016324:Sequence Tagged Sites