Complex chromosomal rearrangement and intracytoplasmic sperm injection: a case report

Complex Chromosomal Rearrangement Causes Male Azoospermia: A Case Report and Literature Review

Background: Male carriers of complex chromosomal rearrangements (CCRs) may have decreased fertility and usually present with azoospermia, oligospermia or teratospermia.

Methods: High-resolution karyotype analysis using G-banding on peripheral blood lymphocytes was performed in an azoospermic male. Copy number variations (CNVs) were detected by chromosomal microarray analysis, and genetic variations were determined by long-read nanopore sequencing with Sanger sequencing for breakpoint confirmation.

Results: The karyotype of the patient was 46,XY,t(4;21)(p11;p11),t(5;6;14)(p13q22;p22q22;q22), which did not involve CNVs with clinical significance. Twelve breakpoints in chromosomes 5, 6, and 14 were found by long-read nanopore sequencing. Reports on 17 males carrying CCRs with azoospermia were also reviewed.

Conclusion: The extent of asynaptic regions in synaptonemal complexes during pachytene and the disruption of genes involved in male gametogenesis may cause azoospermia in CCR carriers.

A family study of complex chromosome rearrangement involving chromosomes 1, 8, and 11 and its reproductive consequences

Complex chromosome translocations are structural chromosomal rearrangements involving three or more chromosomes and more than two breakpoints. A complex chromosome rearrangement was detected in a phenotypically normal female patient that was referred to the hospital for genetic counseling due to reproductive failure. A cytogenetic evaluation was performed, according to standard method of chromosomal analysis, using G-banding technique. The patient's karyotype showed a balanced complex chromosome rearrangement (BCCR) involving chromosomes 1, 8, and 11 with three breakpoints 1p31, 8q13, and 11q23. The karyotype designed according to ISCN (2013), is 46,XX,t(1;8;11)(p31;q13;q23) (8qter→8q13::1p31→1qter;8pter→8q13::11q23→11qter;11pter→11q23::1p31→1pter). Additionally, the proband's mother and brother were tested, resulting in the same exact translocation. In this study, we describe all possible meiotic segregations regarding this translocation, as well as the clinical phenotypes which could arise, if unbalanced products of conception survive. This is a rare case of familial complex chromosome rearrangement, giving a view for its reproductive consequences.

Reproductive outcomes in men with karyotype abnormalities: Case report and review of the literature

Reciprocal translocations of autosomal chromosomes are present in about 1/625 men, yet often there are no symptoms except primary infertility. Abnormal segregation during meiosis often produces sperm and subsequent embryos with unbalanced translocations that often ultimately result in spontaneous abortions. We report on a 37-year-old man and his 39-year-old wife who complained of primary infertility. Previous in vitro fertilization (IVF) had resulted in pregnancy, but two spontaneous abortions. Upon chromosomal testing, the man was diagnosed with a reciprocal translocation and his wife was diagnosed with mosaic Turner's syndrome. Through testicular sperm extraction (TESE) and IVF with preimplantation genetic screening (PGS), they succeeded in having two healthy children. Since men with different karyotype abnormalities can have male infertility, we reviewed the literature and summarized the reproductive outcomes for men with both autosome and sex chromosomal karyotype abnormalities.

Ring chromosome 21 and monosomy 21 mosaicism in a patient with azoospermia

In this report, we describe a patient with azoospermia in conjection with de novo ring chromosome 21 and monosomy 21 mosaicism. Inter-phase fluorescence in situ hybridisation (FISH) studies on uncultured peripheral blood and epithelial cells obtained by buccal smear revealed that 25% of the uncultured blood cells and 11% of the epithelial cells were monosomic for chromosome 21. Y chromosome microdeletion analysis ruled out the presence of any genomic deletions in the azoospermic factor a,b,c regions on the long arm of chromosome Y. Additionally, through subtelomeric FISH analysis, it was found that there was no deletion in the subtelomeric region of ring chromosome 21. Our results indicate that ring chromosome 21 is a rare, but recurrent chromosomal abnormality in male factor infertility. Furthermore, in individuals with ring chromosome 21, defective spermatogenesis is not associated with the deletion of any gene or genes located in the subtelomeric region of chromosome 21.

Sperm selection: effect on sperm DNA quality

The selection of spermatozoa without DNA fragmentation and chromosomal diseases prior to assisted reproductive techniques helps to optimize the outcome of the treatment; in particular, sperm selection prior to in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is crucial. In fact, although ICSI has been successfully and safely applied worldwide for almost 20 years, at the present time we have no real knowledge regarding the hypothetical long-term side effects on ICSI adults, given the increased likelihood of spermatozoa with defective nuclear content fertilizing oocytes.In the case of DNA damage, the basal sperm DNA fragmentation rate can be significantly reduced by some sperm processing procedures that improve the percentage of spermatozoa with normal chromatin structure by filtering out DNA-damaged spermatozoa. After this first step, new advances in micromanipulation can be performed to choose the "ideal" mature spermatozoa for ICSI, reducing potential damage to the gametes. In fact, it is possible to prevent fertilization by DNA-damaged and chromosomal-unbalanced spermatozoa by selecting ICSI sperm by maturation markers such as hyaluronic acid or other zona pellucida receptors. Furthermore, novel noninvasive imaging techniques can be valid tools for helping in the morphological selection of ICSI spermatozoa.

Constitutional complex chromosomal rearrangements in a klinefelter patient: case report and review of literature

BACKGROUNDS

While XXY aneuploidy is the most common disorder of sex chromosomes in men, complex chromosomal rearrangements (CCRs) are rare in humans.

CASE DESCRIPTION

Here we describe clinical and cytogenetic findings in a male referred to our cytogenetic laboratory by an infertility clinic. The patient's age was 35 at the time of referral. Total azoospermia was confirmed on semen analysis.

RESULTS

The karyotype of peripheral blood showed 47,XXY,t(1;3;5)(p22;q29;q22). The mother had the same CCRs.

DISCUSSION

To our best of our knowledge this is the first case of 47,XXY with CCRs. We think it is important to report such a unique chromosomal occurrence.

De novo exceptional complex chromosomal rearrangement in a healthy fertile male: case report and review of the literature

OBJECTIVE

To report a de novo exceptional complex chromosomal rearrangement (CCR) with four breakpoints in the male partner of a couple with recurrent abortions.

DESIGN

Case report and review of the literature.

SETTING

Genetics laboratory in a private hospital.

PATIENT(S)

A couple referred for recurrent abortions.

INTERVENTION(S)

Cytogenetic and sperm fluorescence in situ hybridization (FISH) techniques.

MAIN OUTCOME MEASURE(S)

Karyotype and FISH sperm results.

RESULT(S)

The couple was phenotypically normal, with no family history of miscarriage or infertility. Female karyotype was normal. Male karyotype followed by FISH analysis showed a de novo CCR with four breakpoints: t(5,13,16)(q11.1, q14.3, q12.2), ins(16;13)(q12.2;q?q14.2). ish t(5;13;16)(wcp5+,wcp13+), ins(16;13)(wcp13+).

CONCLUSION(S)

Exceptional de novo CCR male carriers with recurrent abortions are extremely rare. Patients with CCRs have limited options to achieve a normal pregnancy. Careful consideration and assessment should be provided upon counseling of couples with CCRs.

A paternally transmitted complex chromosomal rearrangement (CCR) involving chromosomes 2, 6, and 18 includes eight breakpoints and five insertional translocations (ITs) through three generations

Complex chromosomal rearrangements (CCRs) are uncommon and mainly occur de novo. We report here on a familial CCR involving chromosomes 2, 6, and 18. The propositus is a boy first referred because of growth delays, hypotonia, and facial anomalies, suggestive of deletion 18q syndrome. However, a cytogenetic family study disclosed a balanced CCR in three generations, which was detailed by FISH using BAC clones, and consisted of eight breakpoints with five insertional translocations (ITs). The propositus had a cryptic 18q deletion and a 6p duplication. Paternal transmission of this CCR was observed through three generations without meiotic recombination. Our investigation allowed us to provide porosities counseling and management of prenatal diagnosis for propositus cousin who carries this particular CCR.

Complex chromosomal rearrangement involving chromosomes 1, 4 and 22 in an infertile male: case report and literature review

Here we describe a rare case of an apparently balanced karyotype of 46, XY, t(1;22;4)(p22.3;q11.1;q31.1) in a infertile male with oligoastenoteratozoospermia (OAT). He was the second patient with complex chromosomal rearrangement (CCR) referred to our center because of infertility. We also review reports on 24 males carrying CCRs with spermatogenesis failure or a malformed child, to provide information on the reproductive outcome of male CCR carriers.

A healthy live birth after successful preimplantation genetic diagnosis for carriers of complex chromosome rearrangements

OBJECTIVE

To report a live birth after successful preimplantation genetic diagnosis (PGD) for carriers of complex chromosomal rearrangements (CCRs) with translocation and deletion.

DESIGN

Fluorescent in situ hybridization (FISH) was applied to PGD for CCR carriers.

SETTING

University-based centers for reproductive medicine.

PATIENT(S)

Three CCR carriers, patient A with 46,XX,t(6;10;8)(q25.1;q21.1;q21.1), patient B with 46,X,del(X)(p22.3),t(2;18)(q14.1;q21)[48]/45,X, t(2;18)(q14.1;q21)[12], and patient C with 46,XY,t(5;13;8)(q21.2;q14.3;q24.3).

INTERVENTION(S)

Balanced or normal embryos were diagnosed by PGD and transferred.

MAIN OUTCOME MEASURE(S)

Diagnosis rate of FISH, pregnancy outcome, and karyotype of amniocentesis.

RESULT(S)

Blastomeres were biopsied from 56 embryos in four PGD cycles, and 54 embryos (96.4%) were successfully diagnosed by FISH. Among them, four embryos were diagnosed as transferable in two cycles of patient B and one cycle of patient C. After three cycles of embryo transfer, a pregnancy was achieved in the second PGD cycle of patient B, and the karyotype of amniocentesis was 46,XY,t(2;18)(q14.1;q21). A healthy baby was delivered at 40 weeks of gestation by cesarean section.

CONCLUSION(S)

This is the first report for a live birth after PGD in the CCR carriers associated with translocation and deletion, 46,X,del(X)(p22.3),t(2;18)(q14.1;q21)[48]/45,X,t(2;18)(q14.1;q21)[12]. Preimplantation genetic diagnosis for CCRs needs more consideration and advanced techniques for full karyotyping.