Genetic characterization of two 46,XX males without gonadal ambiguities

Purpose

To evaluate hypotheses which explain phenotypic variability in sex determining region Y positive 46,XX males. We investigate two 46,XX males without gonadal ambiguities.

Methods

Cytogenetic and molecular analyses were used to identify the presence of Y chromosome material and to map the translocation breakpoint. Finally, the pattern of X chromosome inactivation was studied using the methylation assay at the androgen receptor locus.

Results

The presence of Y chromosome material, including the sex determining region Y gene, was demonstrated in both men. However, the amount of translocated Y chromosome material differed between the patients. Different X chromosome inactivation patterns were found in the patients; random in one patient and non-random in the other.

Conclusions

We found a lack of association between phenotype and X chromosome inactivation pattern. Our cytogenetic and molecular analyses show support for the position effect hypothesis explaining the phenotypic variability in XX males.     

Genetic and epigenetic X-chromosome variations in a parthenogenetic human embryonic stem cell line

Purpose

To assess the genetic and epigenetic status of parthenogenetic human embryonic stem cells (phESCs).

Methods

Cytogenetics, X chromosome inactivation (XCI) and gene expression patterns were analyzed in one phESC line (FY-phES-018) that was derived from our laboratory.

Results

FY-phES-018 cells displayed the classical characteristics of normal hESCs. These cells had a 46, XX karyotype, and no inactive X chromosomes were observed before passage 20. After being cultured long term in vitro, some cells lost one X, and the proportion of cells with only one X gradually increased. At passage 35, almost all the cells displayed a 45, XO karyotype. Interestingly, at passage 45, the recovery of the X-chromosome was observed, and XCI became detectable; the mosaic ratio of 46, XX to 45, XO was 67:33. After passage 60, most cells displayed the 46, XX karyotype again with a mosaic ratio of 97:3. Some aberrant genomic imprinting was also observed in these cells.

Conclusions

The phESCs line FY-phES-018 is both genetically and epigenetically unstable; therefore, further research is needed before using these cells.     

Non-chimerism and chimerism pseudo dicentric Y chromosome: two case reports about azoospermia and cytogenetic/molecular genetic analysis in the Chinese population

Objective

To report the cytogenetic and molecular genetic analysis of the first two cases of non-chimerism and chimerism karyotype in Chinese male patients who suffer from azoospermia, which may be caused by pseudo dicentric Y chromosomes.

Design

Case study.

Setting

Academic reproductive medicine center.

Patients

Two male patients with azoospermia, carrying pseudo dicentric Y chromosome.

Interventions

Review the records of inquiry, testicular biopsy, pathological examination, semen routine examination, endocrine evaluation, cytogenetic chromosomal analysis, and FISH detection of peripheral blood to evaluate Y chromosome deletion.

Main outcome measures

To investigate the possible association among pseudo dicentric Y, chimeric status and azoospermia.

Results

Two patients were both diagnosed with azoospermia by a variety of andrology inspections. Further chromosomal analysis and FISH indicated their pseudo dicentric Y chromosome and different chimerism status. PCR confirmed simultaneous deletions of AZFb and AZFc regions in the Y chromosome of both patients.

Conclusions

Pseudodicentric Y chromosome affecting the long arm may lead to a male phenotype by duplicating the sex-determining region of Y chromosome (SRY) fragment and chimeric status may further impact patient's hormone levels, which obstruct spermatogenesis. However, the deletion of the azoospermia factor (AZF) is likely the key factor that causes azoospermia.     

Cytogenetic and Y chromosome microdeletion screening studies in infertile males with Oligozoospermia and Azoospermia in Southeast Turkey

Purpose

In view of the genetic risks for the next generation, the importance of careful evaluation of karyotypes and AZF microdeletions in male infertility prior to assisted reproduction is evident. In the present study, it is aimed to investigate the frequency and types of both major chromosomal abnormalities by using standard cytogenetic methods and Y chromosome microdeletions of infertile males with azoospermia and oligozoospermia to give appropriate genetic counseling before assisted reproduction techniques in southeast Turkey.

Methods

A total of 80 infertile males (52 were azoospermic, 25 oligospermic and 3 asthenospermic) were studied for the cytogenetic evaluation and molecular AZF screening program prior to use of assisted reproduction techniques. A detailed history was taken for each man. Karyotyping was performed on peripheral blood lymphocytes according to standard methods. Polymerase chain reaction (PCR) amplification by using 15 Y-specific sequence-tagged sites of AZF region was performed to screen the microdeletions in the AZF region of Y chromosome.

Results

Of 80 cases, 71 had normal karyotype (46,XY). The total prevalence of chromosomal abnormalities was found to be 11.2% (9/80), including seven patients with Klinefelter syndromes and two patients with balanced autosomal rearrangements. All of the patients with Klinefelter Syndrome had azoospermia, but carriers with translocation had oligospermia. The deletions of Y chromosome were seen in one patient (1.3%) with features of normal karyotype and azoospermia. Microdeletions were seen in the AZFc and AZFd regions. Neither AZFa nor AZFb microdeletions were detected.

Conclusions

The occurrence of chromosomal anomalies and Y chromosome microdeletions among infertile males strongly suggests the need for routine genetic testing and counseling prior to employment of assisted reproduction techniques.     

A novel universal multiplex PCR improves detection of AZFc Y-chromosome microdeletions

Purpose

To determine the frequencies and the characteristics of Y chromosome microdeletions (pl) in infertile men from central China to perform appropriate therapeutic choices by updated multiplex-PCR.

Methods

In this study, we established a novel universal primer-multiplex-PCR (U-M-PCR) method to overcome the disadvantages of traditional multiplex PCR (M-PCR). We chose 15 sequence-tagged sites (STS) for detection of Y chromosome microdeletions. 540 infertile male patients and 100 healthy male controls were selected in the study.

Results

Of the 540 male infertility patients, 48 Y-chromosome microdeletions were detected, with a total deletion rate of 8.9 %. Of these deletions, the rate of AZFa deletions (sY84) was 0.5 % (3/540), the rate of AZFb deletions (sY143) was 0.7 % (4/540) and the rate of AZFc deletions (sY242, sY254 and sY255) was 7.6 % (41/540). Compared with AZF deletion rates by M-PCR, we found U-M-PCR could detect AZFc deletion more specifically (1.0 % & 7.6 %). No Y-chromosome microdeletions were detected in the 100 males with normal semen (the control group).

Conclusions

U-M-PCR method was more specific to detect AZFc microdeletions. It is necessary to use the U-M-PCR method to offer genetic screening and counseling to infertile men prior to intracytoplasmic sperm injection (ICSI) or in-vitro fertilization (IVF).     

A novel chromosomal translocation and heteromorphism in a female with recurrent pregnancy loss—a case study

Purpose

To evaluate the clinical, biochemical and cytogenetic analyses of a couple with reproductive failure.

Methods

A couple with a history of recurrent pregnancy loss was referred to the Institute of Genetics for cytogenetic evaluation. Chromosomal analysis of the phenotypically normal parents was done to ascertain the role of chromosomal abnormalities and offer appropriate genetic counseling. Further, advanced karyotype analysis by spectral karyotyping was also carried out in the couple and parents of the female partner.

Results

Clinical and hormonal profile of the couple revealed normal phenotypes. The ultrasound scan of the female showed normal uterus and ovaries. Chromosomal analysis of the couple revealed a normal 46, XY karyotype in the male spouse, and a unique balanced reciprocal translocation 46, XX, t(12;13) (q13;q33) + 15pstk+ chromosomal constitution in the female partner. Cytogenetic analysis of her parents revealed a similar translocation between chromosomes 12 and 13 in the father and 15pstk+ in the mother. Further, corroboration of the chromosome abnormalities was carried out by spectral karyotyping.

Conclusion

A unique and novel familial transmission of paternally derived balanced reciprocal translocation and maternally derived heteromorphism in a female with the history of recurrent pregnancy loss was reported as an original investigation.     

Cytogenetic abnormalities in 179 cases with male infertility in Western Region of Turkey: Report and review

Purpose

In this study we aimed to evaluate the postnatally screened karyotype results in couples who were referred because of primary infertility between 2000 and 2006 in Izmir.

Methods

The records of a total of 179 cases were evaluated retrospectively.

Results

A total of 21 cases (11.74%) showed chromosomal alteration. Thirteen (7.26%) were 47,XXY; three (1.68%) were pericentric inversion of chromosome 9; one (0.56%) 46,XY/45,XO; one (0.56%) 46,XY/47,XXY/48,XXXY; one (0.56%) 46,XY,t(X;1); one (0.56%) 46,XY/46,XY,del(Y)(q11.2) and one (0.56%) 46,XX.

Conclusions

The rate of gonosomal chromosomal abnormalities was nearly three times higher in our region than the rate in the literature. Chromosomal analysis is strongly suggested particularly in those who suffer fertility problems.     

X-Y translocations and sex differentiation

Translocations involving the X and Y chromosomes are often associated with anomalies of gonadal development. Transfer of Yp sequences, including the testis-determining SRY gene, to the terminal portion of the short arm of the X chromosome is associated with 46,XX maleness and in rare cases 46,XX true hermaphroditism. Three classes of XX males have been defined on the basis of the extent of Y material transferred to the X chromosome. In one class, the transfer of material involves aberrant recombination between two highly homologous genes, PKRX and PKRY, and there is evidence to suggest that this interchange is influenced by the Y chromosome background. Other types of X-Y translocations associated with anomalies of sex differentiation include Xp-Yq translocations, which result in a functional disomy of Xp sequences including the DSS locus and are associated with 46,XY complete or partial gonadal dysgenesis. In rare cases Yp-Xq translocations have been described in association with 46,XX maleness.     

Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome derived from chromosome 11

Objective

We present prenatal diagnosis and molecular cytogenetic characterization of a small supernumerary marker chromosome (sSMC) derived from chromosome 11.

High prevalence of genetic abnormalities in Middle Eastern patients with idiopathic non-obstructive azoospermia

Introduction

Our objective is to detect the frequency and types of major genetic abnormalities of idiopathic non-obstructive azoospermia (NOA) to give appropriate genetic counseling before assisted reproductive techniques (ART) in Middle East and to compare the frequencies with other regions of the world.

Material and methods

A total of 880 Middle Eastern patients with NOA were recruited in this multicenter study for genetic evaluation prior to use of ART. Karyotyping was performed on peripheral blood lymphocytes according to standard G-banding methods, polymerase chain reaction (PCR) was performed to screen the microdeletions in the AZF region of the Y chromosome.

Results

The present study shows that the total prevalence of genetic abnormalities is 28.41 %, including 184 patients (20.91 %) with chromosome disorder and 66 patients (7.5 %) with Y chromosome microdeletions. The most prevalent chromosome abnormality is Klinefelter’s syndrome, which includes 161 patients (18.3 %), 7 patients had XX reversal male sex (0.8 %), 2 patients had 47XYY (0.23 %) and 2 patients had 45XO/46XY (0.23 %). Structural abnormalities occurred in 12 patients (1.36 %).

Conclusions

The high prevalence of genetic abnormalities (28.41 %) in our study strongly suggests the need for routine genetic testing and counseling prior to assisted reproduction in such population with idiopathic infertility, as a result may help determine the prognosis, as well as the choice of ART. Moreover it allows specific pre-implantation genetic testing to minimize the risk of transmitting genetic defects to offspring.     

A 46,XX SRY-negative man with complete virilization and infertility as the main anomaly

OBJECTIVE: To report a case of a 46,XX SRY-negative man with a male phenotype and azoospermia. DESIGN: Case report. SETTING: Molecular and Cytogenetic Unit in a University Hospital. PATIENT(S): A 35-year-old man with complete masculinization who referred to our institution because of a history of several years of infertility. INTERVENTION(S): Lymphocytic karyotype and genetic counseling. MAIN OUTCOME MEASURE(S): Peripheral blood metaphases were analyzed by standard G-banding and Q-banding. Fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR) analyses were performed. RESULT(S): Semen analysis showed azoospermia. Chromosome analysis revealed a 46,XX karyotype; molecular and cytogenetic analyses excluded the presence of SRY (the sex-determining region of the Y chromosome) gene. CONCLUSION(S): This case is one of the rare patients reported in the literature in whom testicular differentiation and a complete virilization in a 46,XX chromosomal constitution does not account for a translocation of the SRY gene to the X chromosome or to the autosomes. This finding suggests that other genes downstream from SRY, not yet identified, play an important role in sex determination.     

Greater prevalence of Y chromosome Q1a3a haplogroup in Y-microdeleted Chilean men: a case–control study

Purpose

To determine the prevalence of South Amerindian Y chromosome in Chilean patients with spermatogenic failure and their association with classical and/or AZFc-partial Y chromosome deletions.

Methods

We studied 400 men, 218 with secretory azo/oligozoospermia (cases) and 182 controls (116 fertile and/or normozoospermic, and 66 azoospermic with normal spermatogenesis). After a complete testicular characterization (physical evaluation, hormonal and/or biopsy) peripheral blood was drawn to obtain DNA for Y chromosome microdeletions, AZFc-partial deletions and biallelic analysis by allele specific polymerase chain reaction (PCR) of the M3 (rs3894) single nucleotide polymorphism (SNP).

Results

Classical AZF microdeletions were found in 23 cases (Y-microdeleted). AZFc-partial deletions were observed in 10 cases (6 “gr/gr”, 3 “b2/b3” and 1 “b1/b3”) and 4 controls (4 “gr/gr”). The AZFc-partial deletions were mainly associated with the absence of DAZ1/DAZ2 (64 %). No significant differences in the prevalence of AZFc-partial deletions were observed between cases and controls. We observed a significant higher proportion of the Q1a3a haplogroup in Y-microdeleted men compared to patients with spermatogenic failure without deletions and control men (P?<?0.01 and P?<?0.05, respectively by Bonferroni test). Among them, patients with AZFb deletions had an increased prevalence of the Q1a3a haplogroup compared to controls, cases without deletions and to those with complete or partial-AZFc deletions (P?<?0.01, Bonferroni test).

Conclusions

The Q1a3a South Amerindian lineage seems to increase the susceptibility to non AZFc microdeletions. On the other hand, in Chilean population the AZFc-partial deletions (“gr/gr”, “b1/b3” and/or “b2/b3”) does not seem to predispose to severe spermatogenic impairment.     

一例罕见SRY阴性46,XX,inv(9)男性

目的:探讨46,XX男性性反转综合征的临床表现和遗传学基础。方法:对1例46,XX,inv(9)(p11q13)男性不育患者进行系统检查,包括精液分析、血清激素和性腺组织活检,PCR法分析SRY基因和Y染色体上包括AZF区域的23个特异性位点,用FISH技术进一步证实患者核型及SRY的缺失,同时检测与性腺分化相关的SOX9和DMRT1基因内部的STR位点,以观察有无基因剂量的改变。结果:外周血淋巴细胞染色体核型分析为46,XX,inv(9)(p11q13)。Y染色体上SRY和其它23个特异位点均为阴性。未发现SOX9和DMRT1基因剂量改变。性腺组织活检证实为发育不良的睾丸组织。由于睾丸组织DNA模板提取失败,故未能检测睾丸组织的特异性位点。结论:本病例的性反转不是由SRY基因转移引起的。性别决定和分化的机制目前还不完全清楚,除了SRY等已知的基因外,可能还存在其它未知但重要的性别决定基因。     

A birth of twins—one boy and one girl—from a single embryo transfer and a possible natural pregnancy

Purpose

To describe a rare case of a birth of dizygotic twins with different-sex infants from a single embryo transfer.

Methods and results

A patient, who had her right ovary and tube removed, and her husband were treated with ICSI and a single embryo transfer. When a single fresh embryo was transferred on day 4, following oocyte retrieval using GnRH agonist-long protocol, two gestational sacs were recognized at 8 weeks of gestation. Healthy twins with a boy and a girl were delivered at 37 weeks 0 days of gestation by a cesarean section. The boy’s weight was 2096g, and his height was 45.0cm, while the girl’s weight was 1988g, and her height was 41.5cm. Peripheral lymphocyte chromosome analysis of the two infants showed normal karyotype, 46, XY (boy) and 46, XX (girl).

Conclusions

A single embryo transfer could produce different-sex twins.     

Male infertility in China: laboratory finding for AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China

Purposes

To investigate the frequencies of AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China. Moreover, to compare the prevalence of these abnormalities with other countries and regions in the world.

Methods

305 infertile men were enrolled. A complete semen analysis and reproductive hormones were measured according to standard methods. Multiplex polymerase chain reaction (PCR) amplification using nine specific sequence-tagged sites (STS) were used to detect AZF microdeletions. Karyotype analyses were performed on peripheral blood lymphocytes with standard G-banding.

Results

Of the 305 infertile men, 28 (9.2%) had AZF microdeletions and 26 (8.5%) had chromosomal abnormalities. The most frequent microdeletions were in the AZFc+d, followed by AZFc, AZFb+c+d and AZFa. A total of 19 patients (82.6%) had Klinefelter′s syndrome (47, XXY) in the azoospermic group.

Conclusions

The freqencies of AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China were comparable with infertile men from other countries and regions. However, there was a slightly higher prevalence rate of AZF microdeletions in oligozoospermic patients than reported in previous studies.     

Monozygotic twins with discordant karyotypes following preimplantation genetic screening and single embryo transfer: case report

Purpose

To report a case of monozygotic monochorial diamniotic twins with discordant karyotypes.

Methods and results

The pregnancy was achieved following a treatment cycle with intracytoplasmic sperm injection (ICSI) and preimplantation genetic screening (PGS) for chromosomes X, Y, 13, 16, 18, 21, 22. One embryo euploid for studied chromosomes was transferred. Prenatal ultrasonography revealed monozygotic twins. One fetus had growth retardation, multiple organ abnormalities and polyhydramnion. The other twin had normal ultrasound appearance. Delivery on week 29 of gestation resulted in the birth of two females, a stillborn twin with karyotype 45,XX,-13[12]/46,XX,r(13)[3] and a healthy twin with normal karyotype.

Conclusions

The discordance in the twins’ karyotypes originated from a mosaic embryo. Structural chromosomal abnormality of the affected twin could not be revealed using standard PGS investigation. Embryo splitting occurred probably due to apoptotic process in an early stage of embryo development. Apoptosis represents one of the possible mechanisms which can explain the embryo twinning process globally.     

Chromosomal abnormalities in men with pregestational and gestational infertility in northeast China

Purpose

To detect incidences and the types of chromosomal abnormalities in Chinese men with infertility and determine chromosomal factors association with various phenotypes.

Methods

Semen analysis and karyotype analysis by G-banding were carried out in 4,659 idiopathic infertile males; additionally, multiplex PCR using nine specific sequence-tagged sites (STSs) was used to detect azoospermia factor (AZF) microdeletions in 412 patients with Y chromosomal abnormalities.

Results

Male infertility was divided into pregestational infertility, characterized by failure to produce a fertilized ovum, and gestational infertility, characterized by embryo loss after fertilization. The former can result from azoospermia, oligozoospermia or oligoasthenozoospermia syndrome, while the latter is associated with developmental early pregnancy loss, habitual miscarriage and stillbirth. Among 4,659 male patients, 412 (8.84 %) showed abnormal chromosomal karyotypes, including 314 (6.74 %) with sex chromosomal abnormalities and 98 (2.10 %) with autosomal abnormalities. The prevalences of numerical and structural abnormalities among patients with chromosomal abnormalities were 259/412 (62.86 %) and 153/412 (37.14 %), respectively. Furthermore, structural sex chromosomal abnormalities were represented by various phenotypic profiles (46,XX, 47,XYY and 45,X/46,XY), and a prevalence of AZF microdeletions of 19/79 (24.05 %). AZF microdeletions were highly associated with Y chromosomal abnormalities (P = 0.018).

Conclusion

Various chromosomal abnormalities that result in male infertility could affect spermatogenesis or embryonic development at different levels. Sex chromosomal and autosomal abnormalities were highly associated with pregestational and gestational infertility, respectively. AZF microdeletions may play an important role in lowering the stability of the Y chromosome.     

Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome derived from chromosome 21q11.2-q21.1 and a literature review

Objective

We present prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome (sSMC) derived from chromosome 21q11.2-q21.1, and we review the literature of an sSMC(21) with a duplication of 21q11.2-q21.1.