Spermatogenesis in an infertile XYY man

Pituitary hyperplasia with Sertoli cell-only and 47,XYY syndromes: an uncommon triad

We report the case history of a 32-year-old man with no phenotypical abnormalities who presented with infertility. Semen analysis revealed azoospermia and testicular biopsy confirmed Sertoli cell-only (SCO) syndrome. Karyotyping revealed 47,XYY and pituitary hyperplasia was found on MRI pituitary. In our patient, 47,XYY karyotype is likely to have given rise to SCO syndrome that in turn resulted in pituitary hyperplasia. The patient was evaluated by various members of the multidisciplinary team including the pituitary surgeon, endocrinologist and andrologist. The patient's partner successfully delivered a healthy baby via in vitro fertilisation with donor sperm. This triad of diagnoses (SCO syndrome, 47,XYY karyotype and pituitary hyperplasia) has not been reported previously. SCO syndrome should be considered in the presence of azoospermia, elevated follicle-stimulating hormone, low inhibin-B and normal testosterone levels. Our case report also highlights the importance of excluding genetic causes of infertility even when the patient has no phenotypical abnormalities.

Reproductive outcomes of 3 infertile males with XYY syndrome: Retrospective case series and literature review

The aim of this study is to evaluate the pregnancy outcomes of males with a 47, XYY karyotype following assisted reproductive treatment.A retrospective study was performed using data from infertile men with 47, XYY at a center for reproductive medicine in 2004 to 2017. Of the 19,842 infertile males treated, a total of 21 showed the 47, XYY karyotype and were included in the present study. Clinical variables were collected. Three men were under treatment with their partner before either in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).The incidence of 47, XYY in infertile men is 1/945 (21/19842). Most men are azoospermic or severely oligospermic. Three men and their partners underwent IVF or ICSI treatment with fresh ejaculate samples. The fertilization rate was 52.94% to 83.33%. The embryo cleavage rate was 50% to 90%. One man had abnormal sex hormonal levels and his partner had no clinical pregnancy. The other 2 couples had healthy baby boys.Live spermatozoa can be gathered and fertility is possible for infertile males with 47, XYY syndrome when IVF or ICSI treatment is used. It is recommended that genetic counseling is provided in such cases.

Molecular cytogenetic characterization of an isodicentric Yq and a neocentric isochromosome Yp in an azoospermic male

Isodicentric Y chromosomes are considered one of the most common structural abnormalities of the Y chromosome. Neocentric marker chromosomes, with neocentromeres, have drawn increasing attention in recent years. The present study reported an azoospermic male with a neocentric isochromosome Yp, neo(Yp), and an isodicentric Yq, idic(Yq). The karyotype was analyzed using G‑banding, chromosome microarray analysis (CMA), and fluorescence in situ hybridization (FISH) with various detection probes, including sex‑determining region on the Y chromosome (SRY) and Y centromeric, applied at the same time. G‑banding initially revealed the karyotype 47,X,i(Y)(q10),+mar. CMA indicated the presence of an extra Y chromosome, seemingly equivalent to 47,XYY males. FISH delineated the existence of two centromeres on the idic(Yq). For the marker chromosome, two SRY signals were detected instead of the Y‑specific centromere signal, and a visual centromere was observed. This indicated the possible existence of a neocentromere in the marker chromosome, located in the connected region in Yp11.2 band. Finally, the patient's karyotype was established as 47,X,idic(Y)(p11.2), neo(Y)(pter→Yp11.2::Yp11.2→pter). The findings suggested that both idic(Yq) and neo(Yp) could be the main causes of the patient's azoospermia, despite the fact that the partial disomy of Ypter to Yp11.2 did not lead to any major malformations. The present study not only improves the understanding of karyotype/phenotype relationships between neocentric marker Y chromosomes and male infertility, but also supports the hypothesis that the combined application of molecular cytogenetic analysis could aid in reliably confirming breakpoints, origins, and the constitution of the marker chromosomes.

Genetic diagnostics of male infertility in clinical practice

Approximately 15% of couples are infertile. Male factors contribute to infertility in over 50% of cases. Identifiable genetic abnormalities contribute to 15%-20% of the most severe forms of male infertility, azoospermia. In this chapter, we explore known genetic causes of male infertility such as Klinefelter syndrome, XYY men, Kallmann syndrome, y-microdeletions, Robertsonian translocations, autosomal inversions, mixed gonadal dysgenesis, x-linked and autosomal gene mutations, and cystic fibrosis transmembrane conductance regulator abnormalities. We also briefly comment on novel biomarkers for male infertility.

Array comparative genomic hybridization analysis of small supernumerary marker chromosomes in human infertility

Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by conventional banding cytogenetics. This study describes four patients with sSMC in relation with infertility. Patient 1 had primary infertility. His brother, fertile, carried the same sSMC (patient 2). Patient 3 presented polycystic ovary syndrome and patient 4 primary ovarian insufficiency. Cytogenetic studies, array comparative genomic hybridization (CGH) and sperm analyses were compared with cases previously reported. sSMC corresponded to the 15q11.2 region (patients 1 and 2), the centromeric chromosome 15 region (patient 3) and the 21p11.2 region (patient 4). Array CGH showed 3.6-Mb gain for patients 1 and 2 and 0.266-Mb gain for patient 4. Sperm fluorescent in-situ hybridization analyses found ratios of 0.37 and 0.30 of sperm nuclei with sSMC(15) for patients 1 and 2, respectively (P < 0.001). An increase of sperm nuclei with disomy X, Y and 18 was noted for patient 1 compared with control and patient 2 (P < 0.001). Among the genes mapped in the unbalanced chromosomal regions, POTE B and BAGE are related to the testis and ovary, respectively. The implication of sSMC in infertility could be due to duplication, but also to mechanical effects perturbing meiosis.

Nonmosaic 47,XYY syndrome presenting with male infertility: case series

In this study, we describe nine patients with 47,XYY presenting with male infertility. All patients were subjected to history taking, clinical examination, duplex ultrasonographic examination of the scrotum, endocrinological investigations and cytogenetic analysis of peripheral lymphocytes. Two patients tried intracytoplasmic sperm injection (ICSI). Our results showed that seven patients were oligospermic and two patients were azoospermic. Bilateral varicocele was detected in seven patients. The hormonal levels in the majority of the patients were within normal range. Two patients showed improvement after varicocelectomy. The wife of one of the oligospermic patients became successfully pregnant after the first trial of ICSI. In conclusion, this report suggests that patients with XYY may present with primary infertility and may show oligospermia and nonobstructive azoospermia. Careful clinical, ultrasonographic, endocrinological and cytogenetic examinations should be a part of their diagnostic work-up for the proper management of these patients. In addition, ICSI may be a hope for some of these patients.

Aneuploidy study in sperm and preimplantation embryos from nonmosaic 47,XYY men

OBJECTIVE

To determine gonosomal and autosomal aneuploidy rate in sperm and preimplantation embryos from nonmosaic 47,XYY males.

DESIGN

Sperm and blastomere analysis by fluorescence in situ hybridization.

SETTING

Fertility clinic, academic hospital.

PATIENT(S)

Two 47,XYY men undergoing preimplantation genetic diagnosis (PGD) and eight 46,XY males distributed in two control groups (fertile and infertile).

INTERVENTION(S)

Sperm-sample collection for fluorescence in situ hybridization and PGD.

MAIN OUTCOME MEASURE(S)

Aneuploidy frequencies for chromosomes X, Y, 13, 16, 18, 21, and 22 in sperm and embryos.

RESULT(S)

Patients with 47,XYY presented global sperm gonosomal and autosomal aneuploidy frequency of 37.23%-37.80%, with XY disomy being the most frequent abnormality (16.70%-19.01%). This aneuploidy rate was statistically significantly different from that found in both 46,XY infertile controls (1.07%) and 46,XY fertile controls (1.04%). In total, 47 preimplantation embryos were analyzed, of which 32 were classified as normal (68%) and 15 as aneuploid (32%). Among the abnormal embryos, 9 presented gonosomal abnormalities, and 6, autosomal abnormalities.

CONCLUSION(S)

High rate of gonosomal and autosomal aneuploidy was observed in sperm and preimplantation embryos from nonmosaic 47,XYY males. The offspring of this category of patients may be at higher risk of chromosomal abnormalities, and therefore PGD can be suggested to these patients.

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.

Segregation of a supernumerary del(15) marker chromosome in sperm

Supernumerary marker chromosomes (SMC) can be associated with both normal and abnormal phenotypes. In addition, SMC are found at higher frequency in males with infertility. We identified a SMC, characterized as a del(15)(q11.2) chromosome, in a phenotypically normal male. Using fluorescence in situ hybridization (FISH), we examined the segregation of the del(15) chromosome in sperm from this patient. Only 6.23% of sperm nuclei showed disomy using a chromosome 15 alpha-satellite FISH probe, instead of the expected 50%. In addition, FISH analysis showed no increase for non-disjunction of chromosome 18, excluding an interchromosomal effect for this chromosome. The significant decrease in sperm bearing the del(15) may be due to tissue-specific mosaicism or a result of some form of selection against the del(15) during spermatogenesis. This finding provides a basis for the observation that SMC(15) are less likely to be inherited from a paternal carrier.

Multicolor fluorescence in situ hybridization analysis of meiotic chromosome segregation in a 47,XYY male and a review of the literature

The frequencies of aneuploid and diploid sperm were determined in a 47,XYY male using multi-color fluorescence in situ hybridization (FISH) analysis, and compared with those from 10 control donors. A total of 30,078 sperm from the patient was scored, 15,044 by two-color FISH for chromosomes 13 and 21, and 15,034 by three-color FISH for the sex chromosomes using chromosome 1 as an internal autosomal control for diploidy and lack of hybridization. The frequencies of X-bearing (49.73%) and Y-bearing sperm (49.46%) in control males were not significantly different from the expected 50% (chi(2)-test for goodness of fit). The ratio of 24,X (50.60%) to 24, Y sperm (48.35%) in the patient, however, was significantly different from the controls (P = 0.0144, chi(2)-test for independence) and from the expected 1:1 ratio (P = 0.0055, chi(2)-test for goodness of fit). There was no significant increase in the frequency of diploid sperm when compared with the controls (chi(2)-test for independence). Significantly increased frequencies were found for 24,YY (0.07% vs. 0.02%, P = 0.0009) and 24,XY (0.44% vs. 0.29%, P = 0.0025), but not for 24,XX (0.05% vs. 0.05%, P > 0. 05), 24,+13 (0.07% vs. 0.07%, P > 0.05) or 24,+21 sperm (0.21% vs. 0. 18%, P > 0.05) in the 47,XYY male when compared with control donors (chi(2)-test for independence). Our results support the theory that loss of the extra Y chromosome occurs during spermatogenesis in most cells. In this XYY patient there was a significant increase in the frequency of sperm with sex chromosomal abnormalities but no suggestion of an inter-chromosomal effect on autosomes. All 3-color FISH studies in the literature demonstrate a significantly increased risk of gonosomal aneuploidy in XYY males, with the risk being on the order of 1%.

Quantified testicular histology in boys with sex chromosome abnormalities

Testicular histology in adult men with Klinefelter's syndrome (KS) is characterized by degenerative changes of the seminiferous epithelium. In contrast, limited changes have been reported in XXY fetuses. However, knowledge about the natural history of the degeneration of testicular histology in KS is scarce, and similarly testicular histology in prepubertal individuals with XY/XXY and XYY karyotypes is described incompletely. We have performed a qualitative and quantitative study of testicular histology in 11 XXY, one XY/XXY mosaic and two XYY boys between the neonatal period and 13 years of age using stereological methods and control data from normal XY boys and XY boys undergoing surgery for testicular maldescent. Testicular specimens were obtained at autopsy (n=2) or at time of surgery for malposition of the testis (n=10) or for inguinal hernia (n=2). The seminiferous tubules showed no sign of degeneration in any of the specimens. The volume density of seminiferous tubules was normal at all ages, whereas mean tubular diameter was reduced in all but three XXY boys. Germ cell numbers were only normal in XXY and XYY infants as well as in the 12 year old mosaic. No germ cells were observed in any XXY boy age 2 years or more. Leydig cells were observed in the infants and in a 13 year old XXY boy. The changes were comparable to what has been found in the most severely affected XY boys with testicular maldescent. We conclude that testicular histology in individuals with sex chromosome aneuploidy seems to be near normal during infancy, after which time degenerative changes occur.

Persistence of two Y chromosomes through meiotic prophase and metaphase I in an XYY man

Studies of spermatogenesis in an XYY male, presenting at a subfertility clinic, confirm the tendency for the germ cells to lose the second Y chromosome but for some XYY cells to reach metaphase I (MI). Light microscope studies of MI revealed the presence of YY bivalents and EM studies of microspread, silver-stained pachytene stages showed 30% of the cells to have two Y chromosomes; 13 out of 16 of these showing a YY synaptonemal complex. Strikingly, the Y axes show only partial synapsis; in no case was synapsis of the long arm heterochromatic regions apparent.

Quantitative histology of human fetal testes in chromosomal disease

Morphometric studies on male gonads were performed in 35 midterm fetuses aborted after prenatal diagnosis of a chromosome anomaly and in 11 chromosomally normal controls. A significant reduction of the number and volume percentage of premeiotic germ cells was observed in the chromosomally abnormal cases. Germ cell depletion was correlated with the severity of the chromosomal disease. It was least expressed in the XYY condition. In trisomy 13 and 18, depletion lead to values of less than a half or even a fourth the values of controls. Complex anomalies with XXY or XYY in addition to an autosomal disorder showed a moderate effect on germ cell reduction. No morphological differences were observed in germ cells or in Sertoli cells in a comparative electron microscopic study. Paucity of fetal germ cells can result from impaired colonization of the gonadal ridge, from low mitotic activity, or from increased premeiotic cell loss. All three factors seem to contribute to the above findings.

Reproduction in XYY males: two new cases and implications for genetic counseling

We present two children--one, 47,XY, + mar, and the other, 47,XY, + 21. Both fathers were found to have a 47,XYY chromosome constitution. The initial assumption was that the fathers' aneuploid conditions contributed to those of the offspring. However, the derivation of the marker chromosome could be paternal, maternal, or postzygotic, and examination of polymorphic structures of the number 21 chromosomes of the child with Down syndrome and his parents suggested maternal derivation of the supernumerary 21. To explore further the reproductive risks of an individual with the XYY constitution, previous reports of reproductive performance and testicular histology are examined as are two theories which suggest XYY males may be at an increased risk of producing aneuploid progeny. Based on these reports, recommendations are made for testing XYY males prior to genetic counseling.

Cytogenetic and histological studies of testicular biopsies from subfertile men with chromosome anomaly

Testicular biopsies from eight men with abnormal karyotypes have been examined for histological and cytogenetic evidence of disturbances of meiosis. Quantitative analysis of this material showed one, with a 13;14 Robertsonian translocation, to have apparently normal spermatogenesis. Three patients, one with a 47,XYY and two with 45,XY, inv 9 karyotypes, had an overall depression of spermatogenesis. Four others, all with major chromosomal abnormalities, had apparently normal spermatogenesis until the primary spermatocyte stage. Two of these had sex autosomal translocations. One, 45,Y,t(X;21), had a complete block at MI, the other, 46,X,t(Y;16), had a partial block at spermatid formation. One man with a reciprocal 2;10 translocation showed delay at all stages beyond spermatocyte formation and one man with an inversion of chromosome 3 showed impaired spermatid maturation.