Chromosome constitution and apoptosis of immature germ cells present in sperm of two 47,XYY infertile males

BACKGROUND: In order to assess sperm alterations observed in some XYY males, we analysed the chromosome constitution as well as apoptosis expression in germ cells from two oligozoospermic males with high count of immature germ cells in their semen. METHODS: Sex chromosome number and distribution were assessed at pachytene stage by fluorescence in situ hybridization (FISH). Immature germ cells and spermatozoa were examined by FISH and TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end (TUNEL) assay, combined with immunocytochemistry using the proacrosin-specific monoclonal antibody (mAb 4D4). RESULTS: For patients 1 and 2, two Y chromosomes were present in respectively 60.0 and 39.6% of pachytenes. The three sex chromosomes were always in close proximity and partially or totally condensed in a sex body. XYY spermatocytes I escape the pachytene checkpoint and achieve meiosis. Nevertheless, nuclear division and/or cytokinesis were often impaired during meiosis leading to diploid (mainly 47,XYY cells) and tetraploid (94,XXYYYY) meiocytes. The presence of binucleated (23,Y)(24,XY) immature germ cells resulting from cytokinesis failure agree with a preferential segregation of the two Y chromosomes during meiosis I. In addition, 69.6% (patient 1) and 53.12% (patient 2) of post-reductional round germ cells were XY. However, high level of apoptotic round germ cells (94.9% for patient 1 and 93.3% for patient 2) was detected and may explain the moderate increase of hyperhaploid XY spermatozoa. Segregation errors also occurred in the XY cell line responsible for disomic 18 and X, as well as 46,XY diploid spermatozoa. CONCLUSIONS: Our data are in agreement with the persistence of the extra Y chromosome during meiosis in XYY oligozoospermic males responsible for spermatogenesis impairment and a probable elimination via apoptosis of most XYY germ cells not solely during but also after meiosis.     

Sperm aneuploidy and meiotic sex chromosome configurations in an infertile XYY male

BACKGROUND: There is little information regarding the behaviour of the extra Y chromosome during meiosis I in men with 47,XYY karyotypes and the segregation of the sex chromosomes in sperm. We applied immunofluorescent and FISH techniques to study the relationship between the sex chromosome configuration in meiotic germ cells and the segregation pattern in sperm, both isolated from semen samples of a 47,XYY infertile man. METHODS: The sex chromosome configuration of pachytene germ cells was determined by immunostaining pachytene nuclei for synaptonemal complex protein 3 (SCP3) and SCP1. FISH was subsequently performed to identify the sex chromosomes and chromosome 18 in pachytene cells. Dual- and triple-color FISH was performed on sperm to analyse aneuploidy for chromosomes 13, 18, 21, X, and Y. RESULTS: 46,XY/47,XYY mosaic pachytene cells were observed (22.2% vs. 77.8%, respectively). The XYY trivalent, and X+YY configurations were most common. While the majority of sperm were of normal chromosomal constitution, an increase in sex and autosome disomy was observed. CONCLUSIONS: The level of germ cell moscaicism and their meiotic sex chromosome configurations may determine sperm aneuploidy rate and fertility status in 47,XYY men. Our approach of immunostaining meiotic cells in the ejaculate is a novel method for investigating spermatogenesis in infertile men.     

Genetics: Constitution of semen samples from XYY and XXY males as analysed by in-situ hybridization

A brightfield microscopical in-situ hybridization (ISH) techniquewas applied to semen samples of two 47,XYY males, one 46,XY/47,XXYmale with fertility problems, and two normal 46,XY men, whoserved as controls. The use of a standardized nuclear DNA decondensationmethod, together with double-target ISH and morphological staining,allowed an accurate study of the sex chromosomal content andmorphology of spermatozoa. In the males carrying an extra sexchromosome, we detected X- and Y-bearing spermatozoa in a ratiowhich did not differ significantly from the .1:1 ratio foundin normal males. Aneuploidy for the sex chromosomes was foundin 15% of the spermatozoa of both XYY males and in 3% of theXXY male. The most striking finding was the relatively low percentageof spermatozoa in these patients, with an average of 65% inthe XYY males and 84% in the XXY male. The other cells representedimmature germ cells (IGC), including spermatogonia and spermatocytesarrested at various stages of spermatogenesis. Apparently, inXYY or XXY men, these IGC are shed into the semen to an increasedextent as compared to normal, fertile men. The sex chromosomeconstitution of these IGC was heterogeneous. However, the findingthat the majority of spermatozoa in semen of 47,XYY and 47,XXYmales carried a single sex chromosome strengthens the hypothesisthat a 46,XY germ cell line must be present, apparently witha proliferative advantage over the 47,XYY or 47,XXY cells.     

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.     

Infant with mos45,X/46,XY/47,XYY/48,XYYY: Genetic and clinical findings

We describe an infant with mos45,X/46,XY/47,XYY/48,XYYY who presented with ambiguous genitalia. Her phenotype was also remarkable for minor ear and eye anomalies and coarctation of the aorta with bicuspid aortic valve. Laparoscopy revealed bilateral Fallopian tubes and a left infantile testis with epididymis. Chromosomal analyses of blood, skin, aorta, right Fallopian tube, and left gonadal tissue showed mos45,X/46,XY/47,XYY/48,XYYY. The 46,XY cell line was identified with routine trypsin-Giemsa banding only in cultured cells from an aortic biopsy. Fluorescence in-situ hybridization (FISH) was utilized to identify the presence of 46,XY cells in other tissues. The clinical manifestations of this patient are discussed and compared with those of similar cases of Y chromosome aneuploidy. To our knowledge, this is the first report of a patient with this unusual karyotype. © 1995 Wiley-Liss, Inc.     

XYY chromosome anomaly and schizophrenia

Sex chromosome anomalies have been associated with psychoses, and most of the evidence is linked to the presence of an additional X chromosome. We report a patient with XYY chromosome anomaly who developed schizophrenia. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 81:64–65, 1998. © 1998 Wiley-Liss, Inc.     

A fluorescent in situ hybridization analysis of the chromosome constitution of ejaculated sperm in a 47, XYY male

Two semen samples from a 47, XXY male were examined using chromosome-specific DNA probes and fluorescent in situ hybridization (FISH) to determine the distribution of sex chromosomes and an autosome (chromosome 17) in the sperm. A motile population of sperm was also prepared from one sample using the swim-up technique to compare the motile and total sperm populations. Chromosomes were localized using single FISH and a biotinylated chromosome 17 probe (TR17), or double FISH using a biotinylated X chromosome probe (TRX) and a digoxigenin-labelled Y chromosome probe (HRY). Labelling efficiencies were 95–98%. Ploidy levels were estimated by measurement against a microscope eyepiece graticule. The overall ratio of X-to Y-bearing sperm was 47% to 48.4% in the neat samples, and 48.4% to 45.3% in the swim-up fraction. Neither of the ratios was significantly different from 1:1. The frequencies of monosomic and disomic (but otherwise haploid sperm) were not different from the frequencies we observed in normal donors. In contrast, the frequencies of both diploid and tetraploid cells were increased in the neat samples of the XYY male. In the swim-up fractions, however, none of these parameters differed from those of ten normal semen donors. These results support the hypothesis that the extra Y chromosome in XYY men is eliminated during spermatogenesis.     

Detection of SRY in 45, X/47, XYY mosaicism leading to phenotypic female

SRY on the Y chromosome initiates male sex determination. We tested a phenotypic female with sex chromosome mosaicism, X/XYY, for SRY expression. SRY was determined by polymerase chain reaction (PCR) amplification in genomic DNA from a female patient with a sex chromosome mosaic complement, 45, X/47, XYY, followed by sequencing analyses. The patient yielded the PCR product with predicted size and homology to the consensus sequence of SRY. The demonstration of SRY provides evidence that the female phenotype in the presence of sex chromosome mosaicism, X/XYY, may result from alterations in another part of the sex-determining pathway or downstream from SRY.     

The development of four unselected 47,XYY boys

Four infants identified through neonatal screening programs are an unselected sample of 47,XYY boys. No consistent physical stigmata or medical disorders were identified. Three have increased height. All four demonstrated problems in motor and language development. Although their intelligence is within the average range, all four have language-related learning disorders requiring special education. Mild depression was apparent in all four, perhaps as a secondary result of their learning disorders. Some of the problems seen in the propositi are found in milder forms in other family members, leading to the hypothesis that their karyotype may heighten vulnerability to pre-existing familial conditions. Similarities between these findings and results from seven other study centers with a total of 42 47,XYY boys are noted. Parents of a prenatally diagnosed 47,XYY fetus seen in our center are informed that the extra Y chromosome represents a risk factor for these problems, but that environment remains a primary force in shaping their child's development.     

Frequency of XYY males in Wisconsin State correctional institutions

Karyotyping of 3011 males at five Wisconsin state correctional institutions revealed that 1 % had a chromosome abnormality. The frequency of occurrence of the XYY complement was about 5 times that for newborn males. Approximately the same rate was found among 2556 males in the three penal institutions for adults. The frequency of XYY at the institution for juvenile offenders was about ten times background. The relatively low frequency of XYY (0.38 %) found at the mental-penal institution may have been due to previous sampling done there. Of the 16 XYY males discovered, only two were below the 85th percentile for height. A relatively low frequency of XYY was found among black males. Our data contradict the notion that a high rate for XYY among adult males in penal settings may be due to a disproportionately large number of tall men in prisons.     

Chromosome changes in mycosis fungoides in an XYY male

A 32-year-old white male was diagnosed as having mycosis fungoides in 1976; bone marrow biopsy and aspiration in August 1984 revealed infiltration with neoplastic cells. Cytogenetic analysis of the cells from the bone marrow specimen showed that 48 of 50 metaphases contained an extra Y chromosome (i.e., 47,XYY). The remaining two cells were hypotetraploid and hyperpentaploid, respectively, with a common marker derived from chromosome #2. The metaphases obtained by PHA stimulation of peripheral blood cells showed a 47,XYY pattern. An interleukin 2 (IL-2) dependent T-cell line was established from the patient's blood mononuclear cells; all metaphases of this line had an extra Y chromosome. Thus, this case is one of a mycosis fungoides developing in an XYY male.     

Testicular function in boys with 47,XYY and relationship to phenotype

An additional Y chromosome occurs in ~1 in 1,000 males, resulting in the karyotype 47,XYY. The phenotype includes tall stature, hypotonia, neuropsychiatric comorbidities, and an increased risk of infertility in adulthood. Little is known about testicular function in childhood and adolescence in 47,XYY. This cross‐sectional study aimed to assess testicular function serum biomarkers, including total testosterone, inhibin B, and anti‐mullerian hormone (AMH), in 82 boys with XYY (11.3 ± 3.8 years) compared with 66 male controls (11.6 ± 3.8 years). The association of testicular hormones with physical features, neuropsychological phenotype, and magnetoencephalography (MEG) was assessed with multiple linear regression models. Results indicate males with XYY have significantly lower inhibin B (median 84 pg/ml vs. 109 pg/ml, p = .004) and higher AMH (median 41 ng/ml vs. 29 ng/ml, p = .011); however, testosterone, testicular volume, and stretched penile length were not different from controls. In the exploratory analysis of relationships between hormone concentrations and phenotypic assessments, higher inhibin B concentrations were positively correlated with lower BMI and better cognitive, academic, and behavioral outcomes in the XYY group. Testosterone concentrations were positively associated with better behavioral outcomes in boys with XYY. Higher testosterone and inhibin B concentrations were also associated with shorter auditory latencies measured using magnetoencephalography (MEG) in XYY. With a few exceptions, testicular hormones were not associated with phenotypic outcomes in controls. In conclusion, there is evidence of subtle impaired testicular function in boys with XYY and a newly described relationship between measures of testicular function and some aspects of the XYY phenotype.     

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.     

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. Received: May 10, 1999 / Accepted: June 22, 1999     

Small noncleaved cell lymphoma in an adolescent with the XYY syndrome

A 19-year-old male was diagnosed with stage III abdominal small noncleaved cell (SNCC) non-Hodgkin lymphoma (NHL). Cytogenetic evaluation of the tumor revealed a complex karyotype which included the t(8;14)(q24;q32), classically associated with this lymphoma histotype, and an extra Y chromosome. After remission was obtained, cytogenetic analysis of bone marrow cells and PHA-stimulated peripheral blood lymphocytes disclosed a normal karyotype except for the persistence of an extra Y chromosome, diagnostic of the XYY syndrome. This is the first reported case of SNCC NHL in an adolescent with the XYY syndrome.     

Discrepancy in mosaic findings between chorionic villi and amniocytes: A diagnostic dilemma involving 45,X, 46,XY,and 47,XYY cell lines

Discrepancies between cytogenetic findings in chorionic villi (CV) and fetal tissue have been reported. Several embryogenic models have been proposed to explain such discrepancies. We describe a case in which analysis of the direct preparation showed 24% 45,X and 76% 46,XY, with 43% 45,X and 57% 46,XY cells in cultured villi. Amniocentesis results disclosed 97% 46,XY and 3% 47,XYY. No 45,X cells were found in cultured amniocytes. These findings suggest that nondisjunction occurred early in postzygotic cleavage resulting in 3 cell lines. It is postulated that through selection, the less viable 45,X cells died out among those destined to become fetus proper but persisted among the cytotrophoblast and extraembryonic mesoderm cells. While there is probably selection against all aneuploid cell lines, 47,XYY cells are more likely to survive in the fetus. An explanation for the lack of 47,XYY cells in the CV might be simply that the tissue sampled was not representative of the cytogenetic make up of the entire placenta. © 1993 Wiley-Liss, Inc.     

DNA synthesis of human XYY cells

The autoradiographic YY labelling pattern of the DNA replication in 47, XYY cells of two patients has been studied. Both Y chromosomes began DNA replication simultaneously but later than the rest of the chromosomes. During later stages the YY labelling pattern in both patients was correlated to the position of the cells in S, as indicated by the cell grain count: in cells with more than approximately 500 grains the synchronous labelling of the Y chromosomes was the rule; whereas during later stages in cells with approximately 100–400 grains, synchronous as well as asynchronous labelling in the same patient was found. In cells with less than about 100 grains, both Y chromosomes usually had completed replication. No obvious difference between the labelling pattern of the two Y chromosomes was found when cells from the 2 patients were compared at the same stage of S. Our results demonstrate the importance of analysing cells of comparable developmental stages of S when comparing DNA labelling patterns of different XYY individuals in search of a possible correlation between labelling pattern and phenotypic expression of the syndrome.
In one of the patients the QM fluorescence pattern as well as the autoradiographic pattern of the same cells was studied. The characteristic intense fluorescence pattern of both Y chromosomes was found even in cells where the autoradiographic labelling pattern indicated distinct asynchrony between the two Y chromosomes. The significance of these findings is discussed.     

Y chromosome gene copy number and lack of autism phenotype in a male with an isodicentric Y chromosome and absent NLGN4Y expression

We describe a unique male with a dicentric Y chromosome whose phenotype was compared to that of males with 47,XYY (XYY). The male Y‐chromosome aneuploidy XYY is associated with physical, behavioral/cognitive phenotypes, and autism spectrum disorders. We hypothesize that increased risk for these phenotypes is caused by increased copy number/overexpression of Y‐encoded genes. Specifically, an extra copy of the neuroligin gene NLGN4Y might elevate the risk of autism in boys with XYY. We present a unique male with the karyotype 46,X,idic(Y)(q11.22), which includes duplication of the Y short arm and proximal long arm and deletion of the distal long arm, evaluated his physical, behavioral/cognitive, and neuroimaging/magnetoencephalography (MEG) phenotypes, and measured blood RNA expression of Y genes. The proband had tall stature and cognitive function within the typical range, without autism features. His blood RNA showed twofold increase in expression of Yp genes versus XY controls, and absent expression of deleted Yq genes, including NLGN4Y. The M100 latencies were similar to findings in typically developing males. In summary, the proband had overexpression of a subset of Yp genes, absent NLGN4Y expression, without ASD findings or XYY‐MEG latency findings. These results are consistent with a role for NLGN4Y overexpression in the etiology of behavioral phenotypes associated with XYY. Further investigation of NLGN4Y as an ASD risk gene in XYY is warranted. The genotype and phenotype(s) of this subject may also provide insight into how Y chromosome genes contribute to normal male development and the male predominance in ASD.     

Chronic myelogenous leukemia with a complex Ph1 translocation in an XYY male

We encountered a 38-year-old Japanese male patient with chronic myelogenous leukemia (CML), whose bone marrow and peripheral blood cells during the chronic and blastic phases contained a complex Ph¹ translocation and an extra Y chromosome [i.e., 47,XYY,t(9;22;13)(q34;q11;q14)]. A karyotypic analysis of PHA-stimulated lymphocytes showed the constitutional karyotype to be 47,XYY. Thus, it was considered that CML with a complex Ph¹ translocation developed in an XYY male; such a case has not been reported, so far. A B-lymphocyte cell line with the complex Ph¹ translocation was established by the procedure of Epstein-Barr virus transformation. The presence of the complex Ph¹ translocation in the B-lymphocyte cell line suggests that some of the B lymphocytes in this patient originated from the CML clone.     

DNA and chromatin structure: Analysis of the sex chromosomal equipment in spermatozoa of a 47, XYY male using two-colour fluorescence in-situ hybridization

The sex chromosomes in spermatozoa of a 47, XYY fertile malewere analysed simultaneously by dual fluorescence in-situ hybridization(FISH), with two probes (pHY2.1 and pXBR). Of the 100 000 cellsanalysed, 95 179 spermatozoa (95.18%) exhibited one or morehybridization signals. Of the hybridized nuclei, 85.37% showeda normal sex chromosome constitution (37.37% X-bearing cellsand 48.00% Y-bearing cells), with an X:Y ratio of 0.78:1. Atotal of 14.63% of the hybridized nuclei exhibited sex chromosomeaneuploidy with a majority of XY-and YY-bearing spermatozoa(9.37 and 4.65% respectively). Even if the majority of spermatozoahave chromosomal haploidy, a large proportion of them exhibitsnumerical errors for the sex chromosomes. These observationsraise questions about the commonly-admitted notions concerningthe absence of chromosomal risk for XYY male offspring. fluorescence interphase in-situ hybridization/sex chromosome/spermatozoa/XYY male