Mosaic ring Y chromosome in two normal healthy men with azoospermia.
OBJECTIVE
To better define by molecular and cytogenetic techniques ring Y chromosomes detected in 2 infertile men.


METHODS
Case report.


METHODS
Molecular genetics/cytogenetics unit in a university hospital.


METHODS
Two infertile men with azoospermia, presenting a normal male phenotype with complete masculinization.


METHODS
Karyotype and genetic counseling.


METHODS
Metaphases were studied by standard G- and Q-banding; fluorescent in situ hybridization and PCR were performed to analyze specific Y chromosome regions.


RESULTS
Chromosomal analysis detected a mosaicism with a Y chromosome ring cell line in 92% (patient 1) and 95% (patient 2) of the metaphases, coexisting with a 45,X cell line in the remaining metaphases. In patient 1, PCR analysis showed the presence of AZFa region and a partial deletion of AZFb region; AZFc region was deleted. In patient 2 all three AZF regions were deleted.


CONCLUSIONS
A 45,X/46,X,r(Y) mosaicism can be detected not only in patients with Ullrich-Turner syndrome and in patients with various degrees of genital ambiguity but also in men presenting a normal phenotype. Their azoospermia can be explained by partial or total deletion of AZF regions.
Bertini
Veronica
V
Laboratory of Cytogenetics and Molecular Genetics, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy.
Canale
Domenico
D
Bicocchi
Maria Patrizia
MP
Simi
Paolo
P
Valetto
Angelo
A
D000328:Adult; D041322:Chromosomes, Human, Y; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009030:Mosaicism; D009845:Oligospermia / Q000235:genetics*; D012303:Ring Chromosomes; D012729:Sex Chromosome Aberrations