Pericentric inversion of chromosome 9: prevalence in 300 Down syndrome families and molecular studies of nondisjunction

Y chromosome polymorphisms contribute to an increased risk of non-obstructive azoospermia: a retrospective study of 32,055 Chinese men

PURPOSE

To investigate the prevalence of Y chromosome polymorphisms in Chinese men and analyze their associations with male infertility and female adverse pregnancy outcomes.

METHODS

The clinical data of 32,055 Chinese men who underwent karyotype analysis from October 2014 to September 2019 were collected. Fisher's exact test, chi-square test, or Kruskal-Wallis test was used to analyze the effects of Y chromosome polymorphism on semen parameters, azoospermia factor (AZF) microdeletions, and female adverse pregnancy outcomes.

RESULTS

The incidence of Y chromosome polymorphic variants was 1.19% (381/32,055) in Chinese men. The incidence of non-obstructive azoospermia (NOA) was significantly higher in men with the Yqh- variant than that in men with normal karyotype and other Y chromosome polymorphic variants (p < 0.050). The incidence of AZF microdeletions was significantly different among the normal karyotype and different Y chromosome polymorphic variant groups (p < 0.001). The detection rate of AZF microdeletions was 28.92% (24/83) in the Yqh- group and 2.50% (3/120) in the Y ≤ 21 group. The AZFb + c region was the most common AZF microdeletion (78.57%, 22/28), followed by AZFc microdeletion (7.14%,2/28) in NOA patients with Yqh- variants. There was no significant difference in the distribution of female adverse pregnancy outcomes among the normal karyotype and different Y chromosome polymorphic variant groups (p = 0.528).

CONCLUSIONS

Patients with 46,XYqh- variant have a higher incidence of NOA and AZF microdeletions than patients with normal karyotype and other Y chromosome polymorphic variants. Y chromosome polymorphic variants do not affect female adverse pregnancy outcomes.

Occurrence of mosaic trisomy 22 and pericentric inversion of chromosome 9 in a patient with a good prognosis

Complete trisomy 22 is a rare chromosomal condition that is incompatible with life. However, mosaic trisomy 22 usually has prolonged survival compatibility and may present a good prognosis depending on the tissues affected. Herein, we described a male patient with the occurrence of mosaic trisomy 22 associated with the inversion of chromosome 9, with karyotype 47, XY, inv (9) (p11q13), + 22 [5] / 46, XY, inv(9) (p11q13) [45] and arr 22q11.1 ~ q13.33(16,417008-51,219,009)x2 ~ 3. It is not possible to infer, in general, the clinical characteristics associated with mosaic trisomy 22. However, the patient presented common clinical features observed in reported cases (in parentheses the percentage observed comparing all reported cases): facial dysmorphia (100%), delay in motor development/growth (82%), cardiac abnormalities (73%), ear abnormalities (55%) and facial and/or body asymmetry (55%), in addition to hypotonia, skin spots, hypoplastic nails. Given the survival and quality of life associated with multidisciplinary treatment, it can be concluded that the patient has a good prognosis. Conclusively, we're presenting the occurrence of mosaic trisomy 22 and chromosome 9 inversion in the patient with favorable prognosis. Thus, this study proposed a guide which should be inserted in databases of rare genetic conditions to help genetic counselors define mosaic trisomy 22 diagnosis.

Effect of chromosomal polymorphisms on the outcome of in vitro fertilization and embryo transfer

PURPOSE

The incidence of chromosomal polymorphisms (CP) is increased in infertile couples, but its impact on reproduction is uncertain, especially undergoing assisted reproductive technology treatment. The purpose of the present study was to investigate the effect of CP on the outcomes of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) treatment METHODS: A total of 1331 infertile couples undergoing IVF/ICSI treatment were involved in this retrospective case-control study. The participants were divided into 4 groups according to CP variations: (i) normal chromosomes (NC) group; (ii) CP group; (iii) both chromosomal polymorphisms (BCP) group; and (iv) double chromosomal polymorphisms (DCP) group. The CP group was further divided into five subgroups: qh+, D/G, inv(9), Yqh+ and Yqh-. The outcomes of IVF/ICSI-ET treatment were compared among the groups.

RESULTS

There were no differences observed between the eight groups in terms of number of oocytes retrieved, MII rate, fertilization rate, cleaved embryo rate, and quality embryo rate for both females and males (p > 0.05). In both male and female, some of the CP subgroups experienced more oocyte retrieval operations and more embryo transfer operations to achieve pregnancy than the NC groups (p < 0.05). The rates of live births were significantly lower in some of the CP subgroups compared to the NC group (p < 0.05).

CONCLUSION

In conclusion, the pregnancy outcomes of ET were affected by CP. It was speculated that this may be associated with the effect of chromosome polymorphism on embryo quality, although this could not be observed or determined by morphological evaluation.

The Interchromosomal Effect: Different Meanings for Different Organisms

The term interchromosomal effect was originally used to describe a change in the distribution of exchange in the presence of an inversion. First characterized in the 1920s by early Drosophila researchers, it has been observed in multiple organisms. Nearly half a century later, the term began to appear in the human genetics literature to describe the hypothesis that parental chromosome differences, such as translocations or inversions, may increase the frequency of meiotic chromosome nondisjunction. Although it remains unclear if chromosome aberrations truly affect the segregation of structurally normal chromosomes in humans, the use of the term interchromosomal effect in this context persists. This article explores the history of the use of the term interchromosomal effect and discusses how chromosomes with structural aberrations are segregated during meiosis.

[Chromosomal polymorphisms are associated with blastomere multinucleation in IVF/ICSI cycles]

OBJECTIVE

To investigate the association of chromosomal polymorphisms with multinucleated embryos in infertile couples undergoing in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI).

METHODS

This retrospective case-control study was conducted among 1145 infertile couples undergoing their first IVF/ICSI cycles. According to their karyotype, the couples were divided into chromosomal polymorphism group and control group, and the former group was divided into 3 subgroups: inversion group, D and G genome polymorphic group and 1, 9, and 16 qh+group. The blastomere multinucleation rate, clinical pregnancy rate and live birth rate were compared between the groups.

RESULTS

Of the total of 1145 couples, 139 (6.10%) had chromosomal polymorphisms at least in one partner. No significant differences were found in female age, BMI, basal FSH level, total gonadotropin dose, E₂ level on day of HCG, number of oocytes retrieved, fertilization rate, top quality embryo rate, clinical pregnancy rate or live birth rate among the groups (P > 0.05). The multinuclear rate of the embryos in couples with pericentric inversion of chromosomes 1, 9, and Y chromosomes and those with D and G genome polymorphisms were 8.23% and 4.65%, respectively, significantly higher than that in the control group (2.69%; P < 0.05); the multinuclear rate of the embryos was 2.77% in 1, 9, and 16 qh+ group, similar with that in the control group (P > 0.05).

CONCLUSIONS

Infertile couples with pericentric inversion of chromosomes 1, 9, and Y chromosomes and in those with D and G genome polymorphism are at higher risks of blastomere multinucleation in IVF- ICSI cycles; 1, 9, and 16 qh + polymorphisms do not increase the rate of blastomere multinucleation of the embryos.

Chromosomal polymorphisms associated with reproductive outcomes after IVF-ET

Purpose

This study aimed to investigate the effect of the detail type of chromosomal polymorphisms (1/9/16qh^+/−, D/G group polymorphisms, and inv(9)) on the IVF-ET outcomes.

Methods

A total of 1335 infertile couples undergoing IVF/ICSI were enrolled and comprehensively analyzed the correlation between three detail types of chromosomal polymorphisms (1/9/16qh^+/−, D/G group polymorphisms, and inv(9)) and the outcome of IVF/ICSI embryo transfer. The fertilized rate, cleaved embryo rate, good-quality embryo rate, clinical pregnancy rate, implantation rate, and early stage miscarriage rate were compared between the chromosomal polymorphisms groups and the control group.

Results

Both the inv(9) and D/G group chromosomal polymorphisms related to female infertility significantly lead to a lower 2PN cleavage rate (86.44% vs. 97.58% and 90.67% vs. 97.58%, respectively, P < 0.05) undergoing IVF insemination, the inv(9) adversely increasing the early miscarriage rate, either undergoing IVF (21.4% vs. 3.0%, P < 0.05) or ICSI (50.0% vs. 2.0%, P < 0.05) insemination, female carriers (23.08% vs. 2.87%, P < 0.05) or male carriers (44.44% vs. 2.87%, P < 0.05). For D/G groups, ICSI insemination may increase the implantation rate (44.8% vs. 23.69%, P < 0.05) and clinical pregnancy rate (78.6% vs. 40.65%, P < 0.05). 1/9/16qh^+/− had no apparent adverse effect on the patient’s clinical outcomes.

Conclusions

Our study suggests that chromosome karyotype analysis is necessary for IVF patients in clinical practice; we should afford individual genetic counseling suggestion according to the polymorphism types.

Novel pericentric inversion inv(9)(p23q22.3) in unrelated individuals with fertility problems in the Southeast European population

Pericentric inversions are among the known polymorphisms detected in the general population at a frequency of 1-2%. Despite their generally benign nature, pericentric inversions affect the reproductive potential of carriers by increasing the risk for unbalanced live-born offspring, miscarriages, or other fertility problems. Here we present a novel large pericentric inversion of chromosome 9, inv(9)(p23q22.3), detected in 30 heterozygote carriers, 24 from seven apparently unrelated families and 6 isolated patients, where the probands were mainly referred for fertility and prenatal problems. The inversion carries a significant risk for recombinant abnormal chromosomes, as in two families one supernumerary rec(9)dup(9p) and one rec(9)dup(9q) were identified, leading to neonatal death and miscarriage, respectively. The inversion carriers were identified by three different laboratories in Greece, Cyprus and Germany respectively, however all carriers have Southeast European origin. The inversion appears to be more frequent in the Greek population, as the majority of the carriers were identified in Greece. We were able to determine that the inversion is identical in all individuals included in the study by applying a combination of several methodologies, such as karyotype, fluorescence in situ hybridization (FISH), chromosomal microarrays (CMA) and haplotype analysis. In addition, haplotype analysis supports that the present inversion is identical by descent (IBD) inherited from a single common ancestor. Our results are, therefore, highly indicative of a founder effect of this inversion, presumably reflecting an event that was present in a small number of individuals that migrated to the current Southeast Europe/Northern Greece from a larger population.

The analysis of chromosomal abnormalities in patients with recurrent pregnancy loss, focusing on the prognosis of patients with inversion of chromosome (9)

PURPOSE

Inversion of chromosome 9 (inv[9]) is considered to be a normal variant, and the inv(9) in patients or husbands with recurrent pregnancy loss (RPL) is believed to be harmless. However, there are few reports concerning the outcomes of pregnancy in patients with RPL when the patient or their partner has inv(9). In this study, we analyzed the outcomes of pregnancy in this patient population.

METHODS

Chromosomal karyotyping was performed for 2006 couples with RPL (two or more consecutive early pregnancy losses including non-visualized cases) with their informed consent. The frequency of various chromosomal abnormalities in the patient population was then analyzed, and the outcomes of pregnancy in patients with inv(9) were investigated.

RESULTS

The frequency of inv(9) in the overall population was 2.6% (52/2006). Thus far, 32 patients have conceived repetitively, resulting in live births in 23 cases and early pregnancy losses in nine cases. Four of the nine cases obtained a good outcome in the subsequent pregnancy. Thus, a successful outcome was obtained in 27 of the 32 (84.4%) cases.

CONCLUSIONS

This study suggests that inv(9) has no adverse influence on subsequent pregnancy.

Pericentric inversion of chromosome 9 causing infertility and subsequent successful in vitro fertilization

One of the most common and benign variants of normal human karyotype is pericentric inversion of chromosome 9 (inv[9][p11q13]). Despite being categorized as a normal variant, there are several reports of its association with various disease conditions. Here, we report a 27 year old female, who presented to us with primary infertility. The woman was diagnosed with inv (9)(p11q13) which was acknowledged as the reason for her otherwise unexplained infertility. The couple thereupon underwent in vitro fertilization using donor oocyte resulting in live birth. The clinical significance of this minor chromosomal rearrangement, need for genetic counseling, and subsequent reproductive guidance is highlighted in this report.

De novo pericentric inversion of chromosome 9 in congenital anomaly

PURPOSE

The pericentric inversion of chromosome 9 is one of the most common structural balanced chromosomal variations and has been found in both normal populations and patients with various abnormal phenotypes and diseases. The aim of this study was to re-evaluate the clinical impact of inv(9)(p11q13).

MATERIALS AND METHODS

We studied the karyotypes of 431 neonates with congenital anomalies at the Pediatric Clinic in Ajou University Hospital between 2004 and 2008 and retrospectively reviewed their clinical data.

RESULTS

Chromosomal aberrations were detected in 60 patients (13.9%). The most common type of structural abnormality was inv(9)(p11q13), found in eight patients. Clinical investigation revealed that all eight cases with inv(9)(p11q13) had various congenital anomalies including: polydactyly, club foot, microtia, deafness, asymmetric face, giant Meckel's diverticulum, duodenal diaphragm, small bowel malrotation, pulmonary stenosis, cardiomyopathy, arrhythmia, and intrauterine growth restriction. The cytogenetic analysis of parents showed that all of the cases were de novo heterozygous inv(9)(p11q13).

CONCLUSION

Since our results indicate that the incidence of inv(9)(p11q13) in patients with congenital anomalies was not significantly different from the normal population, inv(9)(p11q13) does not appear to be pathogenic with regard to the congenital anomalies. Some other, to date unknown, causes of the anomalies remain to be identified.

Behavioral and developmental characteristics of children with inversion of chromosome 9 in Korea: a preliminary study

The purpose of this study is to examine the behavioral and developmental characteristics of children with inv(9). This case control study included 12 inv(9) subjects and 45 normal students. All of the subjects, together with their parents, underwent a psychiatric interview and parent questionnaire consisting of a Child Behavior Checklist (CBCL). The mean scores with regard to the social problems and total problems profiles of the CBCL were significantly higher in the inv(9) group than in the normal control group. The inv(9) group exhibited language and motor developmental delay. These findings suggest that there is a possibility of inv(9) being associated with child developmental or behavioral problems.

Unusual segregation products in sperm from a pericentric inversion 17 heterozygote

Chromosome segregation and interchromosomal effect were studied in spermatozoa from a carrier of a pericentric chromosome 17 inversion, 46,XY,inv(17)(p13.1q25.3). Sperm chromosome segregation, lymphocytes of the inversion carrier, and cells from his offspring were analysed by multicolour fluorescence in situ hybridization. The frequency of balanced sperm was 73%. An unusual segregation of recombinants was observed, viz. deletion of the p arm (14.6%) or duplication of the p arm with the presence of one q arm (8.4%), instead of the expected recombinants, viz. duplication of one arm with deletion of the other and vice versa. These unusual recombinants were explained by the position of the 17q breakpoint, which was between the q arm telomere-associated repeats and the unique q subtelomere region. The offspring of the donor were found to have a 17p deletion including the Miller-Dieker critical region, similar to the most frequent recombinant sperm class. The disomy frequency was significantly increased for chromosome 17 compared with other autosomes, suggesting that pairing and recombination of the inversion may predispose to non-disjunction. There was no significant difference between the frequencies of aneuploidy for chromosomes 13, 21, X and Y in the chromosome inversion heterozygote compared with controls. Thus, this unique pericentric inversion of chromosome 17 produces unusual recombinant products; no evidence was apparent of an interchromosomal effect in any of the tested chromosomes.

Schizophrenia with pericentric inversion of chromosome 9: a case report

A case of schizophrenia according to the DSM-III-R criteria with pericentric inversion of chromosome 9 was reported. This case and the review of the literature indicate that the pericentric region of chromosome 9 might be one of the potential regions of interest for linkage analysis of psychiatric disorders.