Cytogenetic and molecular genetic analysis of dicentric Y chromosome and its relation to male azoospermia|
Omrani, Mir Davood; Hagh, Javad Karimzad; Klein, Wolfrom & Gebauer, Jurgen
Cytogenetic analysis, Y-chromosome microdeletion screening, FISH
techniques and other genetic methods have helped in finding the causes of infertility in
azoospermic or severe oligoazoospermic cases in the last decade.
In the present study, we characterized an abnormal Y-chromosome, detected
as a mosaic in an azoospermic male ascertained for infertility.
Materials and Methods:
Chromosome analysis, using G, Q and C banding techniques
and FISH analyses with several different DNA probes specific for Y and X
chromosome sequences [XY centromeric α-satellite, Y non-α-satellite III, LSI-probes of
the Y chromosome, WCP of Chromosome Y, SRY gene, subtelomeric Xp and Yp,
which cover the SHOX (short stature-homeobox containing) gene, and subtelomeric Xq
and Yq probes] were performed. A total of 20 sequence tagged sites were analyzed
using primer sets specific for the Y-chromosome microdeletion loci. The primers were
chosen to cover AZFa, AZFb, and AZFc regions as well as the SRY gene.
Chromosome analysis revealed a gonosomal mosaicism of monosomy X
(51%) and a pseudodicentric Y (49%) chromosome: mos 45, X/46,X psu dic (Y)
(qter→p11.32 :: p11.2→qter).
Molecular genetic studies did not show deletions in the AZFabc regions, but a deletion
was found in the short arms of the dicentric Y chromosome. One of the SRY genes was
The azoospermia in this patient could be explained by either the presence
of an abnormal Y-chromosome that cannot form a sex vesicle (which appears to be
necessary for the completion of meiosis process and the formation of sperm), or the
presence of the 45, X cell line.
Dicentric Y chromosome, Dic (Yq), FISH, Mosaicism, Azoospermia.