Cases reported "XYY Karyotype"

Filter by keywords:



Filtering documents. Please wait...

1/5. prader-willi syndrome in a child with XYY.

    We report a 26-month-old boy with XYY syndrome, with the complication of prader-willi syndrome (PWS) due to uniparental maternal disomy of chromosome 15. To our knowledge, this is the first case of XYY syndrome and PWS. Clinical findings were fully compatible with the diagnostic criteria for PWS. Molecular analysis revealed a maternal heterodisomy of chromosome 15, indicating that non-disjunction of chromosome 15 had occurred at maternal meiosis I, and that the non-disjunction of chromosome Y and of chromosome 15 had occurred independently.
- - - - - - - - - -
ranking = 1
keywords = meiosis
(Clic here for more details about this article)

2/5. From spermatocytes to spermatozoa in an infertile XYY male.

    Sex chromosome distribution and aneuploidy as well as germ cell degeneration were evaluated in meiotic and post-meiotic cells from an infertile XYY male. Sex chromosome distribution was assessed by multicolour fluorescence in situ hybridization on meiotic preparations. Post-meiotic cell aneuploidy was characterized by a method combining multicolour fluorescence in situ hybridization and immunocytochemistry using the proacrosin-specific monoclonal antibody (mAb 4D4). TUNEL assay was carried out on seminiferous tubules to evaluate germ cell degeneration. At the prophase stage of the first meiotic division, 63.64% of cells at the pachytene stage carried three sex chromosomes. The ratio of X-bearing to Y-bearing spermatids and spermatozoa differed significantly from 1 : 1 with an excess of Y-bearing spermatids and spermatozoa. The frequency of hyperhaploid XY spermatids was increased in the XYY male, as well as the incidence of YY, XY and disomic 18 ejaculated spermatozoa. A preferential elimination of germ cells by apoptosis occurred in spermatocytes I. The persistence of the extra y chromosome during meiosis of an XYY male is associated with a high rate of spermatocyte I degeneration and a low rate of aneuploid spermatozoa.
- - - - - - - - - -
ranking = 1
keywords = meiosis
(Clic here for more details about this article)

3/5. Synaptic behaviour of sex chromosome in two XYY men.

    Analysis of meiotic pairing behavior in two XYY males presenting at subfertility clinic brings evidence that the abnormal mode of pairing caused by the presence of the extra y chromosome, disturbs achievement of spermatogenesis resulting in severe oligoastheno-teratozoospermia. In contrast, the loss of the supernumerary Y before meiosis, allows achievement and normal sperm production.
- - - - - - - - - -
ranking = 1
keywords = meiosis
(Clic here for more details about this article)

4/5. Meiotic behaviour of sex chromosomes investigated by three-colour FISH on 35,142 sperm nuclei from two 47,XYY males.

    Meiotic segregation of sex chromosomes from two fertile 47,XYY men was analysed by a three-colour fluorescence in situ hybridisation procedure. This method allows the identification of hyperhaploidies (spermatozoa with 24 chromosomes) and diploidies (spermatozoa with 46 chromosomes), and their meiotic origin (meiosis I or II). Alpha-satellite probes specific for chromosomes X, Y and 1 were observed simultaneously in 35,142 sperm nuclei. For both 47,XYY men (24,315 sperm nuclei analysed from one male and 10,827 from the other one) the sex ratio differs from the expected 1:1 ratio (P < 0.001). The rates of disomic Y, diploid YY and diploid XY spermatozoa were increased for both 47,XYY men compared with control sperm (142,050 sperm nuclei analysed from five control men), whereas the rates of hyperhaploidy XY, disomy X and disomy 1 were not significantly different from those of control sperm. These results support the hypothesis that the extra y chromosome is lost before meiosis with a proliferative advantage of the resulting 46,XY germ cells. Our observations also suggest that a few primary spermatocytes with two Y chromosomes are able to progress through meiosis and to produce Y-bearing sperm cells. A theoretical pairing of the three gonosomes in primary spermatocytes with an extra sex chromosome, compatible with active spermatogenesis, is proposed.
- - - - - - - - - -
ranking = 3
keywords = meiosis
(Clic here for more details about this article)

5/5. Increased incidence of disomic sperm nuclei in a 47,XYY male assessed by fluorescent in situ hybridization (FISH).

    Using triple-colour fluorescent in situ hybridization in decondensed sperm heads, we assessed the sex-chromosome distribution in spermatozoa from a 47,XYY male compared with controls. The incidence of spermatozoa with 24,XY (0.30%) and 24,YY (1.01%) disomy was significantly higher than in our control series. Diploid meiocytes present in the ejaculate were mainly 47,XYY (60.6-86.7%), and haploid meiocytes were mainly 24,XY (78.1%).These results suggest that, although the extra y chromosome is thought to be eliminated during spermatogenesis, XYY germ cells can complete meiosis and produce disomic spermatozoa.
- - - - - - - - - -
ranking = 1
keywords = meiosis
(Clic here for more details about this article)


Leave a message about 'XYY Karyotype'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.