Molecular and cytogenetic characterization of a structural rearrangement of the Y chromosome in an azoospermic man

Objective: To better define an abnormal karyotype found in a male with primary infertility. Design: Case report. Setting: Molecular and cytogenetics unit in a university-affiliated hospital. Patient(s): A 41-year-old, azoospermic, but otherwise healthy male. Intervention(s): Lymphocytic karyotype and genetic counseling. Main Outcome Measure(s): Metaphases were studied by standard G- and Q-banding, followed by fluorescence in situ hybridization (FISH) and polymerase chain reaction to analyze specific Y chromosome regions. Result(s): Chromosomal analysis and FISH allowed us to define the propositus's karyotype as 45,X/46,X,idic(Yp)/46,XY (71%, 26%, and 3% of analyzed metaphases, respectively). Molecular analysis of azoospermic factor (AZF) regions showed deletion of AZFb and AZFc. Conclusion(s): A 45,X/46,X,idic(Yp) mosaicism is associated with a very broad spectrum of phenotypes, including patients with Ullrich-Turner syndrome, patients with various degrees of genital ambiguity, or normal males. In the presence of a normal masculinization in otherwise healthy males azoospermia is a distinct feature that can be explained by partial deletion of AZF regions.