1/7. Meiotic behaviour of the sex chromosomes in three patients with sex chromosome anomalies (47,XXY, mosaic 46,XY/47,XXY and 47,XYY) assessed by fluorescence in-situ hybridization.Meiotic studies using multicolour fluorescent in-situ hybridization (FISH) and chromosome painting were carried out in three patients with sex chromosome anomalies (47,XXY; 46,XY/47,XXY and 47,XYY). In the two patients with klinefelter syndrome, although variable percentages of XXY cells (88.5 and 28.3%) could be found in the pre-meiotic stages, none of the abnormal cells entered meiosis, and all pachytenes were XY. However, the abnormal testicular environment of these patients probably resulted in meiotic I non-disjunction, and a certain proportion of post-reductional cells were XY (18.3 and 1.7%). The fact that none of the spermatozoa were XY also suggests the existence of an arrest at the secondary spermatocyte or the spermatid level. In the XYY patient, most (95.9%) premeiotic cells were XYY. The percentage of XYY pachytenes was 57.9%. The sex chromosomes were either in close proximity (XYY) or the X chromosome was separated from the two Ys (X YY). A high proportion (42.1%) of post-reductional germ cells were XY. However, only 0.11% of spermatozoa were disomic for the sex chromosomes. In this case, the data suggest the existence of an arrest of the abnormal cells at the primary and the secondary spermatocyte or the spermatid level, giving rise to the continuous elimination of abnormal cells in the germ-cell line along spermatogenesis. The fact that the proportion of diploid spermatozoa was only increased in one of the three cases (XXY) is also suggestive of an arrest of the abnormal cell lines in these patients. The two apparently non-mosaic patients were, in fact, germ-cell mosaics. This suggests that the cytogenetic criteria used to define non-mosaic patients may be inadequate; thus, the risk of intracytoplasmic sperm injection in apparently non-mosaics may be lower than expected.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/7. Mitotic and meiotic behaviour of a naturally transmitted ring y chromosome: reproductive risk evaluation.BACKGROUND: The mitotic and meiotic behaviour of a transmitted ring Y [r(Y)] chromosome from a father to his klinefelter syndrome (KS) son, and the mechanism of ring formation are analysed herein. To our knowledge, this is the first reported case of natural transmission of an r(Y). methods AND RESULTS: Amplification of X chromosome polymorphisms by PCR showed that the KS was of paternal origin. G-banding and fluorescence in situ hybridization (FISH) studies revealed a similar percentage of mosaicism in father and son by mitotic loss of r(Y). SRY gene and Y marker amplification by PCR, FISH with subtelomeric probes for Xp/Yp and Xq/Yq, and comparative genomic hybridization (CGH) analyses indicated the intactness of the y chromosome from SRY to subtelomere Yq. FISH analysis of sperm from the father showed significantly higher frequencies (P<0.005) for diploidy and for 6, 13, 18, 21, 22, XX, XY disomies than those observed in control donors. CONCLUSIONS: An r(Y) with low material loss can be naturally transmitted, showing similar mitotic behaviour in the offspring. The presence of an r(Y) chromosome in germinal cells increased the risk of fathering offspring with numerical abnormalities, even for chromosomes not involved in the arrangement.- - - - - - - - - - ranking = 1.5keywords = behaviour (Clic here for more details about this article) |
3/7. klinefelter syndrome and associated fragile-X syndrome.During screening of male individuals for Fragile-X syndrome in a residential facility for persons with mental retardation, the authors found a 21-year-old profoundly retarded man who displayed facial features and behaviour suggestive of Fragile-X syndrome. The chromosome analysis revealed 47,fra(X)(q27)fra(X)(q27)Y. His physically and intellectually normal sister had 14% of X chromosomes with a fragile site. Her two sons, who were subsequently examined, were found to have Fragile-X syndrome. Thus, the identification of Fragile-X syndrome in the proband during the screening process of a large institution led to the investigation of the proband's family and the subsequent diagnosis of Fragile-X syndrome in the proband's two nephews. The ascertainment of the two affected boys permitted prompt introduction of early intervention and special education services. Genetic counselling of other at-risk family members was carried out.- - - - - - - - - - ranking = 0.25keywords = behaviour (Clic here for more details about this article) |
4/7. A variant chromosome 17 in a mother with repeated abortions and a 46, XY/47, XXY Klinefelter son.A female with a satellited chromosome 17 is presented. She had suffered repeated abortions and later gave birth to a 46,XY/47,XXY Klinefelter boy. The significance of the variant chromosome 17 in the etiology of the mother's reproductive failure is discussed. The mental and physical development of her now 8-year-old 46,XY/47,XXY son has been checked regularly since birth. The boy showed a significant deviation in behaviour pattern and development of body habitus already from early infancy.- - - - - - - - - - ranking = 0.25keywords = behaviour (Clic here for more details about this article) |
5/7. Two cases of 48,XXYY: with discussion on the behaviour of prepubertal and postpubertal patients.Two cases of 48,XXYY are presented, one prepubertal and the other postpubertal. Their dysmorphic features are described and compared to those reported previously. Xg blood grouping was uninformative in determining the origin of the extra X chromosome. The differences in prepubertal and postpubertal behaviour problems are discussed.- - - - - - - - - - ranking = 1.25keywords = behaviour (Clic here for more details about this article) |
6/7. An XYY boy with short stature and a case of Klinefelter's syndrome (XXY) in a family with inversion 9.A patient with Klinefelter's syndrome and a boy with XYY sex chromosomes were both found to have a pericentric inversion of chromosome 9. An unusual feature of the XYY patient was that he presented because of short stature and disturbed behaviour. A family study showed that the patients were related and that there was an excess of males in the pedigree. Another member of the family was found to have some XYY cells in the blood.- - - - - - - - - - ranking = 0.25keywords = behaviour (Clic here for more details about this article) |
7/7. Klinefelter's syndrome with atypical presenting features.The authors thought it would be of interest to present this case which proved to be Klinefelter's syndrome with "xxy" pattern, as the patient presented with episodes of abnormal behaviour lasting for a few minutes. Ho would suddenly become anxious, look perplexed, start clenching his fists and at times complain of thoughts tha some persons were trying to attack him. He also felt as if he were hearing voices talking to him. observation in the hospital and EEG recording helped to rule out temporal lobe epilepsy and a diagnosis of Klinefelter's syndrome with personality disorder and psychogenic attacks of abnormal behaviour was made at the time of discharge.- - - - - - - - - - ranking = 0.5keywords = behaviour (Clic here for more details about this article) |