Pseudodicentric 22;Y translocation transmitted through four generations of a large family without phenotypic repercussion

Preimplantation genetic testing results of blastocysts from 12 non-Robertsonian translocation carriers with chromosome fusion and comparison with Robertsonian translocation carriers

OBJECTIVE

To investigate the effects of non-Robertsonian translocation with chromosome fusion (N-RBCF) on preimplantation embryos.

DESIGN

Case series.

SETTING

University-affiliated center.

PATIENT(S)

Twelve couples with N-RBCF.

INTERVENTION(S)

Assisted reproduction with preimplantation genetic testing in chromosomal structural rearrangement (PGT-SR).

MAIN OUTCOME MEASURE(S)

Normal embryo rate, unbalanced translocation rate.

RESULT(S)

PGT was performed in 12 N-RBCF carriers, of whom 4 carried Y-autosome fusions and 8 autosomal fusions. A total of 12 (63.2%) of 19 blastocysts exhibited normal/balanced embryos, and only one (5.3%) embryo exhibited unbalanced translocations among Y-autosome fusion cases. In contrast to these findings, the percentage of normal/balanced blastocysts in 8 autosomal N-RBCF cases was 28.2% (11/39), whereas the unbalanced translocation rate was 53.8%. Furthermore, the percentage of normal/balanced embryos in the Robertsonian translocation group was significantly higher than that of the 8 autosomal N-RBCF (48.7% vs. 28.2%) cases. The rates of abnormality from chromosomal fusion in the 8 autosomal N-RBCF cases were significantly higher than those noted in the Robertsonian translocation (53.8% vs. 31.4%) subjects. The results of the stratified analysis according to the carrier's sex demonstrated that the rates of unbalanced translocation were significantly higher in the male autosomal N-RBCF subjects than those from the corresponding Robertsonian translocation (55% vs. 19.7%) cases.

CONCLUSION(S)

A low number of unbalanced translocations was identified in blastocysts from N-RBCF subjects who carried the Y fusion. The risk of unbalanced translocation in autosomal N-RBCF was higher than that of the Robertsonian translocation, notably in male carriers.

Molecular cytogenetic studies of a male carrier with a unique (Y;14) translocation: Case report

BACKGROUND

Chromosome translocation is a genetic factor associated with male infertility. However, cases of Y chromosome/autosome translocation are rare. Individuals with translocation between the Y chromosome and an autosome have a variety of different clinical phenotypes. There is a need for further study of molecular cytogenetic feature of those with Y chromosome translocation.

METHODS

We reported that an apparently healthy 31-year-old man, 168 cm tall and weighing 65 kg, had a 2-year history of primary infertility after marriage. Clinical diagnostic techniques included semen analysis, hormone measurements, cytogenetic analysis, fluorescence in situ hybridization (FISH), and high-throughput multiplex ligation-dependent probe amplification semiconductor sequencing. Detailed genetic counseling was provided to the patient. Intracytoplasmic sperm injection treatment combined with preimplantation genetic diagnosis was chosen with the aim of achieving a successful pregnancy.

RESULTS

Semen analysis revealed cryptozoospermia. Hormone levels were within the normal limits. Sequencing results indicated the presence of the sex-determining region on Yp, and AZFa, AZFb, and AZFc regions on Yq. The patient's karyotype was 45,X,psu,dic(Y;14)(p11.3;q11.2), which was confirmed by cytogenetic analysis and FISH.

CONCLUSION

This study reports a case of cryptozoospermia in a male patient with a Y;14 chromosomal translocation. When clinical karyotyping has revealed potential Y chromosome abnormality, FISH or molecular detection should be further performed to facilitate identification of the chromosomal breakpoint.

Cytogenetic and molecular detection of a rare unbalanced Y;3 translocation in an infertile male: A case report

INTRODUCTION

The infertile male individuals carrying the Y-autosome translocations are seldom reported in clinic. Herein, we described a severe oligozoospermic male with rare unbalanced Y;3 translocation transmitted through 3 generations.

PATIENT CONCERNS

A 33-year-old Chinese male was referred for infertility consultation in our center after 10 years' primary infertility. He was diagnosed as severe oligozoospermia according to the semen analysis.

DIAGNOSIS

G-banding analysis initially described the karyotype as 46, XY, add (3) (p26) for the patient, and his wife's karyotype was 46, XX. The chromosomal microarray analysis identified 3.81Mb and 0.29Mb duplications in Yq11.223q11.23 and Yq12, separately. No deletions were detected in azoospermia factors (AZF)a, AZFb and AZFc. Fluorescence in situ hybridization analysis further confirmed the existence of sex-determining region Y gene and verified that Yq12 was translocated to the terminal short arm of chromosome 3(3p26).

INTERVENTIONS

The couple chose intracytoplasmic sperm injection to get their offspring. The wife underwent amniocentesis for cytogenetic analysis but suffered termination of pregnancy due to premature rupture of membranes.

OUTCOMES

The karyotype of the patient was finally described as 46, X, der(3)t(Y;3)(q11.22;p26). His father and the aborted fetus showed the same karyotypes as the patient.

CONCLUSION

Our study not only enriched the karyotype-phenotype correlation of Y-autosome translocation, but also strengthened the critical roles of molecular genetic techniques in identifying the chromosomal breakpoints and regions involved.

The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The World Health Organization (WHO) defines infertility as the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy within one year. Statistics show that the two sexes are equally at risk. Several causes may be responsible for male infertility; however, in 30–40% of cases a diagnosis of idiopathic male infertility is made in men with normal urogenital anatomy, no history of familial fertility-related diseases and a normal panel of values as for endocrine, genetic and biochemical markers. Idiopathic male infertility may be the result of gene/environment interactions, genetic and epigenetic abnormalities. Numerical and structural anomalies of the Y chromosome represent a minor yet significant proportion and are the topic discussed in this review. We searched the PubMed database and major search engines for reports about Y-linked male infertility. We present cases of Y-linked male infertility in terms of (i) anomalies of the Y chromosome structure/number; (ii) Y chromosome misbehavior in a normal genetic background; (iii) Y chromosome copy number variations (CNVs). We discuss possible explanations of male infertility caused by mutations, lower or higher number of copies of otherwise wild type, Y-linked sequences. Despite Y chromosome structural anomalies are not a major cause of male infertility, in case of negative results and of normal DNA sequencing of the ascertained genes causing infertility and mapping on this chromosome, we recommend an analysis of the karyotype integrity in all cases of idiopathic fertility impairment, with an emphasis on the structure and number of this chromosome.

Cytogenetic and molecular characterization of an oligoasthenozoospermia male carrier of an unbalanced Y;22 translocation: A case report

RATIONALE

Y;autosome translocations are associated with male infertility and azoospermia. Some carriers with a Y:22 translocation can produce offspring and transmit the translocation through generations without phenotypic repercussion. Hence, the clinical features of carriers with certain Y chromosome abnormalities remain uncertain.

PATIENT CONCERNS

An apparently healthy 33-year-old man, 175 cm tall and weighing 60 kg had a 6-month history of primary infertility.

DIAGNOSES

The patient was diagnosed with oligoasthenozoospermia. A series of examinations have been performed to evaluate possible genetic causes of this diagnosis. Several methods included semen analysis, hormone measurements, cytogenetic analysis, and high-throughput multiplex ligation-dependent probe amplification semiconductor sequencing.

INTERVENTIONS

The patient underwent detailed genetic counseling. Cytogenetic analysis was advised for his father. Preimplantation genetic diagnosis was performed to improve potential pregnancy success rate.

OUTCOMES

Semen analysis revealed oligoasthenozoospermia. Hormone levels were within the normal limits. The karyotype of the patient and his father was 45,X,der(Y;22). Sequencing results indicated the presence of the sex-determining region on the Y chromosome gene. Y-chromosome microdeletion detection showed the presence of AZF (azoospermic factor)a, AZFb, and AZFc regions, but deletion of b2/b3 and duplication of b3/b4 regions.

LESSONS

A clinical karyotype report involving a Y chromosome abnormality should consider the results of semen analysis, which helps to identify the chromosomal breakpoint. Semiconductor sequencing technology was useful for clarifying AZF gene microdeletions.

45,X karyotype in an infertile man: how is this possible?

The case was male, 32 years old, with a nonobstructive azoospermia diagnosis and an initial 45,X karyotype. We evaluated by classical cytogenetic methods, C and NOR banding, fluorescent in situ hybridization, and polymerase chain reaction investigations. After investigation, we found the following karyotype: 45,X,dic(Y;22)(q11.223;p11.2). This investigation contributes to our understanding of how chromosome rearrangements can influence fertility processes and how important it is to perform a cytogenetic analysis in infertility cases.