Pericentric Inversion Of Chromosome Research Articles

Translocations and inversions: major chromosomal rearrangements during Vigna (Leguminosae) evolution.

Inversions and translocations are the major chromosomal rearrangements involved in Vigna subgenera evolution, being Vigna vexillata the most divergent species. Centromeric repositioning seems to be frequent within the genus. Oligonucleotide-based fluorescence in situ hybridization (Oligo-FISH) provides a powerful chromosome identification system for inferring plant chromosomal evolution. Aiming to understand macrosynteny, chromosomal diversity, and the evolution of bean species from five Vigna subgenera, we constructed cytogenetic maps for eight taxa using oligo-FISH-based chromosome identification. We used oligopainting probes from chromosomes 2 and 3 of Phaseolus vulgaris L. and two barcode probes designed from V. unguiculata (L.) Walp. genome. Additionally, we analyzed genomic blocks among the Ancestral Phaseoleae Karyotype (APK), two V. unguiculata subspecies (V. subg. Vigna), and V. angularis (Willd.) Ohwi & Ohashi (V. subg. Ceratotropis). We observed macrosynteny for chromosomes 2, 3, 4, 6, 7, 8, 9, and 10 in all investigated taxa except for V. vexillata (L.) A. Rich (V. subg. Plectrotropis), in which only chromosomes 4, 7, and 9 were unambiguously identified. Collinearity breaks involved with chromosomes 2 and 3 were revealed. We identified minor differences in the painting pattern among the subgenera, in addition to multiple intra- and interblock inversions and intrachromosomal translocations. Other rearrangements included a pericentric inversion in chromosome 4 (V. subg. Vigna), a reciprocal translocation between chromosomes 1 and 5 (V. subg. Ceratotropis), a potential deletion in chromosome 11 of V. radiata (L.) Wilczek, as well as multiple intrablock inversions and centromere repositioning via genomic blocks. Our study allowed the visualization of karyotypic patterns in each subgenus, revealing important information for understanding intrageneric karyotypic evolution, and suggesting V. vexillata as the most karyotypically divergent species.

Detection of chromosome aberrations in 17 054 individuals with fertility problems and their subsequent assisted reproductive technology treatments in Central China.

How do the types and frequency of chromosome aberrations in couples in central China affect fertility and ART treatment? Men with chromosome aberrations or polymorphisms have an increased risk of semen quality impairment and infertility, and couples affected by reciprocal translocations had a lower pregnancy rate compared with other chromosome aberrations. Karyotyping is crucial for patients affected by infertility as chromosome aberrations play an important role in the etiology of male infertility. However, the influence of chromosome aberrations and polymorphisms on sperm motility and morphology remains controversial. Data on ART treatment outcomes in infertile couples affected by chromosome aberrations are insufficient. We conducted a retrospective study involving 17 054 patients affected by infertility who underwent karyotyping in our center between January 2020 and May 2022. Karyotyping was performed on 17 054 patients with reproductive failure. All patients were from the central regions of China. The following data were collected from a medical records system using patient identification numbers: couples' ages, history of pregnancy and childbirth, type of infertility, years of infertility, cause of infertility, chromosome karyotypes, semen analysis results, assisted reproductive techniques performed, and treatment outcomes of ART. The incidence of chromosome aberrations was 2.04%; 2.49% in men and 1.57% in women. By analyzing the relationships between chromosome aberrations/polymorphisms and abnormal semen parameters, we found that there were significantly higher rates of asthenozoospermia, oligospermia, and teratozoospermia among men with Robertsonian translocations and sex chromosomal structural aberrations compared with those with normal karyotypes. Higher rates of asthenozoospermia and teratozoospermia were also observed among men with autosomal reciprocal translocations. The incidence of chromosome aberrations in azoospermic men (13.75%), and in men with cryptozoospermia or severe oligospermia (6.97%) was significantly higher than that in men with mild oligospermia or normospermia (0.88-2.12%). In addition, we found that the progressive movement of sperm is impaired in men with Chromosome 21 polymorphisms compared with men with normal karyotypes (39.46% ± 20.51% vs 48.61% ± 18.76%, P = 0.026). The percentage of morphologically normal forms was lower in the chromosomal polymorphism group than in the normal karyotype group (5.01% ± 2.41% vs 5.59% ± 2.14%, P = 0.001), especially in men with polymorphisms on Chromosome 9 (enlarged Chromosome 9 heterochromatin [9qh+]: 4.48% ± 2.22% vs 5.59% ± 2.14%, P = 0.006; pericentric inversion of Chromosome 9 [inv(9)]: 5.09% ± 3.11% vs 5.59% ± 2.14%, P = 0.008). ART treatment was successful in 36.00% of couples affected by chromosome aberrations. However, couples affected by reciprocal translocations achieved a lower pregnancy rate (24.07%), which may be due to the lower euploidy rates (27.31%) when compared with that in other chromosome aberrations. First, although the initial cohort was large, chromosome aberrations were identified in a small number of patients. Second, the observational nature of the study design is limiting. Third, the couples affected by infertility in this study were all outpatients that did not undergo identical comprehensive examinations except for karyotyping, leading to the incomplete collection of medical records. Also, the population included in this study mainly focused on couples affected by infertility, which may not be included in the European Association of Urology (EAU) recommendation on male infertility. Men with chromosome aberrations or polymorphisms have an increased risk of semen quality impairment and infertility. Constitutional chromosome analysis is recommended for men affected by infertility and severe oligospermia or azoospermia to facilitate early and appropriate guidance for the most suitable treatment. Carriers of chromosome aberrations can achieve acceptable pregnancy outcomes through IVF. However, couples affected by reciprocal translocations have lower pregnancy rates, and more treatment cycles are needed before a successful pregnancy. A possible explanation may be the fewer euploid embryos obtained. This work was supported by Grant 2021YFC2700603 from the National Key Research & Development Program of China. The authors declare no conflicts of interest. N/A.

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.

Experience in prenatal ultrasound diagnosis of fetal microtia and associated abnormalities.

Prenatal ultrasound features, associated anomalies and genetic abnormalities of microtia cases were analyzed to explore the feasibility and value of prenatal ultrasound for the diagnosis of microtia. The ultrasonographic features, associated anomalies, chromosome examination results and follow-up results of 81 fetuses with congenital microtia were analyzed retrospectively. Among the 81 fetuses with microtia diagnosed after birth, 2 cases were missed diagnosis on prenatal ultrasound, and 1 case was diagnosed as unilateral microtia by prenatal ultrasound but was found to be bilateral microtia after birth. Microtia was accompanied by an accessory auricle in 4 cases (4.94%) and low-set ears in 7 cases (8.64%). 22 cases (27.16%) were complicated with other structural anomalies, including 11 cases (13.58%) of cardiac anomalies, 7 cases (8.64%) of ultrasonographic soft marker anomalies, 6 cases (7.41%) of facial anomalies, 6 cases (7.41%) of nervous system anomalies, 3 cases (3.70%) of urogenital system anomalies, 3 cases (3.70%) of digestive tract anomalies and 2 cases (2.47%) of limb anomalies. Chromosome karyotype analysis and gene detection were performed in 44 cases. Trisomy 18, trisomy 13, trisomy 21, pericentric inversion of chromosome 9, partial loss of heterozygosity on chromosome 14, 22q11 microdeletion and a normal karyotype were found in 2 cases, 2 cases, 3 cases, 1 case, 1 case, 1 case, and 34 cases, respectively. In summary, microtia is often accompanied by congenital defects of other organs and structures, especially the heart and face, and prenatal ultrasound diagnosis of microtia and associated anomalies is of important clinical significance.

P-549 Paraclinical and spermogram evaluation of infertile males with balanced chromosomal rearrangements referred to Royan institute from 2009-2021

Abstract Study question Whether balanced chromosomal rearrangements are associated with altered semen parameters/increased DNA Fragmentation Index (DFI), are the common breakpoints related to male infertility in patients ? Summary answer Balanced chromosomal rearrangements is associated with abnormal semen parameters and increased DFI in carriers. Chromosomes 9,1,3 showed the highest incidence of chromosomal rearrangement What is known already Among many factors, balanced chromosomal rearrangements are thought to be one of the major genetic factors influencing male infertility which can cause disorders related to spermogram, DNA fragmentation, increased risk of miscarriage and ART failure. Finding common chromosomal breakpoints in infertile men carrying balanced chromosomal translocations is significant since these patients usually possess normal clinical features. Numerous studies have been performed on the various chromosome translocations. However, there has not been any report on the common breakpoints in balanced chromosomal abnormalities related to male infertility in Iran. Study design, size, duration This cross-sectional study performed on 25000 patients’ files admitted to the Royan institute during the period 2009- 2021.Infertile men carrying balanced chromosomal rearrangements were included as case group. Sperm parameters, DFI and common chromosomal break points were evaluated Participants/materials, setting, methods 25000 files of patients were reviewed. 252 infertile men carrying balanced chromosomal rearrangements and 252 men with normal karyotype were included (case and control group, respectively). Sperm concentration, motility (CASA), sperm morphology (Papanicolaou Staining),DFI (SCSA) and cytogenetic analysis of peripheral blood lymphocytes (G-banding) were evaluated. Numerical chromosomal abnormalities, deletions, marker chromosomes, alcohol or drug addiction, smoking, chemotherapy and radiation, varicocele and exposure to environmental pollution were excluded. The common chromosomal breakpoints in translocations were investigated. Main results and the role of chance Sperm concentration, total motility and normal morphology were significantly lower in balanced chromosomal rearrangements carriers compared to control group(p < 0.05). DFI in patient was significantly higher in comparison to control group(p < 0.05). Among different kind of chromosomal rearrangement carriers’, sperm concentration and total motility were lower in Robertsonian translocation carriers comparing to the Reciprocal translocation and inversion ones. The reciprocal translocation and inversion carriers did not differ regarding to sperm concentration and total motility. Meanwhile, normal morphology was lower in the translocation compared to inversion carriers. No difference was observed in DFI among carriers of balanced chromosomal rearrangements. Among case group, inversion accounted for the largest share, followed by Reciprocal, Robertsonian translocation and insertion. Group C had the highest frequency in reciprocal translocation, inversion and insertion among the chromosomal groups. The highest balanced translocation prevalence was related to three chromosomes 9,3, and1. 9q12,1p36,3p11 were the most frequent breakpoints among them. Chromosome 9 had the largest contribution to inversions,22 to reciprocal translocations and14 to Robertsonian translocations. In the Robertsonian translocation, group D showed the highest frequency. Interestingly, patients carrying normal variations such as pericentric inversion of chromosome 9showed a significant alteration in sperm parameters, therefore normal variations showed a possible relationship to infertility. Limitations, reasons for caution In order to achieve stronger statistical results on DFI, a larger sample size would be more helpful. Wider implications of the findings The results may be useful to identify the most common breakpoints and consequently genes related to male infertility and can suggest appropriate molecular mechanism for their infertility. Trial registration number not applicable

Pericentric inversion of chromosome 6 and male fertility problems.

As a significant chromosomal structural abnormality, chromosomal inversion is closely related to male infertility. For inversion carriers, the interchromosomal effect explains male infertility, but its specific mechanism remains unclear. Additionally, inversion carriers with different chromosomes have different clinical manifestations. Therefore, genetic counseling is difficult in clinical practice. Herein, four male carriers of pericentric inversion in chromosome 6 have been described. Two patients showed asthenospermia, one showed azoospermia, and the wife of the remaining patient had recurrent miscarriages. Through a literature search, the association between the breakpoint of pericentric inversion in chromosome 6 and male fertility problems are also discussed in this study. Overall, important genes related to asthenospermia in chromosome 6p21 were found, which may be related to the clinical phenotype. These results suggest that physicians should focus on the breakpoints of inversion in genetic counseling.

Pericentric inversion of chromosome 9: an abnormal phenotype

Pericentric inversion of chromosome 9 is considered a ba­lanced structural anomaly. More often cited as a rela­tive­ly common part of the normal human karyotype, this chromosomal rearrangement could correlate with in­fer­ti­lity, abortions and different abnormal clinical conditions. A 5-month-old infant was admitted to our hospital for poor feeding and loose stools. The physical examination revealed an underweight boy (under the fifth percentile) with pla­gio­ce­pha­ly, dysmorphic and low-set ears, hypertelorism, sad­dle nose and micrognathia. The abnormal phenotype also contained long limbs, arachnodactyly, pilonidal sinus and a systolic ejection murmur in the pulmonic area. He was unresponsive to auditory stimuli. The ENT exa­mi­na­tion described bilateral sensorineural hearing loss. Based on dysmorphic appearance and karyotyping of pe­ri­phe­ral, the case was classified as a pericentric inversion of chro­mo­some 9 (p11q13). Despite being categorized as a clinically in­si­gni­fi­cant variant to a cytogenetic finding, further research is still needed for the few cases where specific pathologies were associated with pericentric inversion of chromosome 9.

A rare Y-autosome translocation found in a patient with nonobstructive azoospermia: Case report

ABSTRACT Y‑autosome translocations are relatively uncommon in humans, with t(Y;1) stated to be even rarer. On the contrary, pericentric inversion 9 is the most commonly seen inversion of chromosome . Although considered to have no significant effect on male fertility, the literature reporting on reproductive risks for both aberrations remains controversial. We report here, as far as we know, the first case of a unique combination of balanced reciprocal translocation t(Y;1) with pericentric inversion of chromosome 9 in a patient with nonobstructive azoospermia (NOA) and an otherwise normal phenotype. Our patient was a 37-year-old Caucasian male sent to our Department due to azoospermia reported by semen analysis. The cytogenetic analysis revealed a balanced reciprocal translocation including chromosomes Y and 1 in all observed metaphases: 46, X,t(Y;1)(q12;q21) and a pericentric inversion of chromosome 9: inv(9)(p12q13). By performing metaphase FISH, the t(Y;1) translocation was confirmed. By means of multiplex-PCR, no Y-chromosome microdeletions were detected in the AZF regions. This report demonstrates a unique karyotype showing balanced reciprocal translocation t(Y;1)(q12;q21) with pericentric inversion 9: inv(9)(p12q13), in a patient with NOA, and highlights the importance of appropriate genetic counseling for patients with regard to the medical management of balanced chromosomal aberrations.

Cytogenetic evaluation of orofacial clefts

Background: Orofacial cleft (OFC) is one of the common congenital anomalies of the face which includes cleft lip and or cleft palate that causes abnormal appearance of the face. It leads to difficulty in speech and feeding, especially in new-borns. Genetic and nongenetic factors may lead to OFCs. An association of OFC to genetic cause was assessed in the study. Methodology: Conventional karyotyping was done in 133 patients of all the age groups with OFCs (syndromic and nonsyndromic) to find out chromosomal aberrations (CAs) in OFCs, Department of Oral and Maxillofacial Surgery, MGM Dental College, Navi Mumbai directed patients to cytogenetic laboratory. Project was started after taking consent and ascent from the patient and institutional ethical approval. Results: The incidence of CAs is 2.2%, and polymorphic variations are 3.7%. Out of 133 patients 47, XXY was seen in one case and trisomy 21 was seen in two cases, polymorphic variations like pericentric inversion in chromosome 9, 16qh + and 22 pstk + were observed in one case each and 9qh+ was seen in two cases. Conclusion: The incidence of genetic involvement in terms of CAs and polymorphic variations to OFC is low. The application of molecular technique in patients with OFC will help to find out genetic involvement. Genetic counseling and precise prenatal diagnosis will prevent the incidence of OFC.

CRISPR-Cas9-mediated 75.5-Mb inversion in maize.

CRISPR-Cas is a powerful double-strand-break technology with wide-ranging applications from gene discovery to commercial product development. Thus far, this tool has been almost exclusively used for gene knockouts and deletions, with a few examples of gene edits and targeted gene insertions. Here, we demonstrate the application of CRISPR-Cas9 technology to mediate targeted 75.5-Mb pericentric inversion in chromosome 2 in one of the elite maize inbred lines from Corteva Agriscience. This inversion unlocks a large chromosomal region containing substantial genetic variance for recombination, thus providing opportunities for the development of new maize varieties with improved phenotypes.

A new cytotype for the El Carrizo deer mouse Peromyscus ochraventer

Peromyscus ochraventer is a rodent species endemic of Mexico. In 1981, Robbins and Baker described its karyotype from one single female which presented 2n = 48 and FN = 60. In this paper we describe the Y chromosome of the male and a new cytotype for the species, 2n=48, FN= 58, that was identified in all of the collected specimens. The FN = 58 is due to one pericentric inversion in chromosome 6, as shown by G-banding pattern.

Pericentric inversion in chromosome 1 and male infertility.

Pericentric inversion in chromosome 1 was thought to cause male infertility through spermatogenic impairment, regardless of the breakpoint position. However, carriers of pericentric inversion in chromosome 1 have been reported with normal fertility and familial transmission. Here, we report two cases of pericentric inversion in chromosome 1. One case was detected in utero via amniocentesis, and the other case was detected after the wife of the carrier experienced two spontaneous abortions within 5 years of marriage. Here, the effect of the breakpoint position of the inversion in chromosome 1 on male infertility is examined and compared with the published cases. The association between the breakpoint of pericentric inversion in chromosome 1 and spermatogenesis is also discussed. Overall, the results suggest that the breakpoint position deserves attention from physicians in genetic counseling as inversion carriers can produce offspring.

22q13 Microduplication Syndrome in Siblings with Mild Clinical Phenotype: Broadening the Clinical and Behavioral Spectrum

Distal duplication 22q (22q13.3qter) is a rare condition with only 24 cases described so far. Parental balanced reciprocal translocations and pericentric inversions involving chromosome 22 predispose to the conception of an unbalanced offspring and are more frequently reported than de novo events. The clinical phenotype of patients is highly variable and does not necessarily correlate with the extent of the duplicated segment. Short stature, microcephaly, hypertelorism, cleft lip or palate, low-set ears, and intellectual disability seem to be the most consistent features. Familial reoccurrence is extremely rarely reported. Here, we report 2 siblings with a 22q13.3qter duplication detected by array CGH; their mother is a carrier of a pericentric inversion in chromosome 22. Their relatively mild phenotype and identical chromosomal breakpoints as well as duplication size are unique. This is the first case described so far.

Presence of pericentric inversion in chromosome 9 in all family members

Pericentric inversion is the most common type of inversion encountered in human beings. Although pericentric inversion in chromosome 9 is generally considered as normal variant without any phenotypic presentations, some conditions associated with it, like mental retardation. In the present case, we discuss a baby with mental retardation showing pericentric inversion of chromosome 9 and also parents showing the same type of inversion on chromosome 9 without any phenotypic presentations.

Effects of chromosome 9 inversion on IVF/ICSI: A 7-year retrospective cohort study.

BackgroundThis study focused on the outcomes of patients with pericentric inversion of chromosome 9 who underwent IVF/ICSI and fresh day 2 or day 3 embryo transfer and the possible impacts of carrier gender and chromosome karyotype on pregnancy outcomes.MethodsA total of 214 couples (107 couples with one pericentric inversion of chromosome 9 in one partner [Group 1], 107 couples with normal karyotypes [Group 2]) underwent their first IVF/ICSI treatment and were included in this study. Oocyte number, normal fertilization rates, abnormal fertilization rates, cleavage rates, embryo utilization rates, fresh embryo transfer rates, clinical pregnancy rates (CPR), implantation rates, miscarriage rates, and live birth rates per embryo transfer (LBR) were compared between groups.ResultsGroup 1 did not show any disadvantage when compared with Group 2. The CPR and LBR were similar between all groups. The female carrier group had a higher normal fertilization rate and higher utilization rate than the male carrier group. Cases with inv(9)(p12;q13) had a lower utilization rate but a higher implantation rate than the remaining karyotypes.ConclusionIn the first IVF or ICSI cycle, couples with one pericentric inversion of chromosome 9 in one partner had satisfactory outcomes. The subgroup analysis showed a tendency of better prognosis for the female carrier and inv(9)(p12;q13) type.

Results of preimplantation genetic testing for aneuploidies as a basis for parental karyotypes correction

Introduction Chromosomal abnormalities are the most common genetic cause of infertility. An information about karyotypes of patients undergoing in vitro fertilization (IVF) is not always known. Therefore, IVF patients can be potential carriers of structural chromosomal rearrangements. We report three cases, in which results of preimplantation genetic testing for aneuploidies (PGT-A) allowed us to suspect the presence of parental reciprocal translocations. In each case, the parental reciprocal translocation was confirmed. Material & Methods PGT-A was performed by microarray comparative genomic hybridization (aCGH) (24sure, Illumina) or by next generation sequencing (NGS) (VeriSeq, Illumina). Indications for preimplantation testing were advanced maternal age (case 1 and 2) and paternal pericentric inversion of chromosome 10 (case 3). Parental karyotypes were not known before PGT-A in cases 1 and 2. In case 3 patients’ karyotypes was known before PGT-A and were 46,XX and 46,XY,inv(10)(p11.2;q22). The trophectoderm biopsy was performed at 5-6 day of embryo development. Analysis of parental karyotypes after obtaining PGT results was performed by standard cytogenetic study or by fluorescence in situ hybridization (FISH) on peripheral blood lymphocyte culture. The choice of method of parental karyotypes analysis was determined by size of the embryo chromosomal imbalance. Results PGT-A results showed a nonrandom pattern of segmental loses and gains in each case (table 1). These facts were the basis for parental karyotypes analysis. It was confirmed, that in each case one of the couple was the carrier of reciprocal translocation. In case 1 a paternal reciprocal translocation between chromosomes 11 and 22 was found – 46,XY,t(11;22)(q23.3;q13). In case 2 a maternal reciprocal translocation between chromosomes 10 and 12 was found – ish t(10;12)(D10S2290-, D12S158+; D10S2290+, D12S158-). In case 3 a maternal reciprocal translocation between chromosomes 2 and 12 was found - ish t(2;12)(D2S2147-,D12S399+; D2S2147+, D12S399-). Table 1 Case № Number of embryos Number of embryos with nonrandom pattern of segmental abnormalities Chromosomes involved in nonrandom segmental abnormalities Case 1 5 3 Chromosomes 11 and 22 Case 2 4 4 Chromosomes 10 and 12 Case 3 4 3 Chromosomes 2 and 12 Conclusions It is very importantto draw attention to pattern of segmental chromosomal abnormalities of embryos. 24-chromosome aneuploidy testing is not only an actual method for detection of embryo chromosomal imbalance, but in some cases also can help to correct parental karyotypes.

Prenatal diagnosis and genetic counseling for two pedigrees with pericentric inversion of chromosome 18

Objective To investigate the roles of ultrasound, laboratory methods, and genetic diagnostic techniques in screening and diagnosing fetuses with an unbalanced recombination of chromosome 18[rec(18)] due to parental pericentric inversion, and the relationship between rec(18) fetal phenotypes and their recombinant chromosomes. Methods We analyzed two pedigrees with pericentric inversion of chromosome 18 (including the fetuses and their parents) which received prenatal diagnosis and genetic counseling on March 2017 and March 2018 respectively at Xiamen Maternity and Children Health Care Hospital through karyotype analysis, chromosome microarray analysis(CMA) and fluorescence in situ hybridization (FISH). Literatures were retrieved from Scientific Citation Index, PubMed, China National Knowledge Infrastructure(CNKI) and Wanfang Data from 1970 to June 2018. The genetic counseling records, ultrasound and laboratory findings, pregnancy outcomes of families with pericentric inversion of chromosome 18 in this study and the included literatures were reported and analyzed. Results Non-invasive prenatal testing (NIPT) of one case indicated high risk of fetal trisomy 18 at 22 weeks of gestation. And the imaging examination indicated that fetus had interventricular septal defect and micrognathia at 24+2 weeks. Prenatal diagnosis confirmed that the fetal karyotype was 46,XY,rec(18)dup(18q)inv(18)(p11.32q12.1) pat, which was originated from his father whose karyotype was 46,XY,inv(18)(p11.32q12.1). In the other case, serum screening testing indicated high risk of fetal trisomy 18 at 12+3 weeks. Imaging examination indicated that fetus had thickened nuchal translucency at 13+3 weeks and bilateral choroid plexus cysts at 15+6 weeks. Prenatal diagnosis confirmed that the fetal karyotype was 46,XY,rec(18)dup(18q)inv(18)(p11.32q12.1) mat, which was originated from his mother whose karyotype was 46,XX,inv(18)(p11.32q12.1). Among the nine fetuses, including seven from five pedigrees reported in the literature retrieved and two from the two pedigrees we reported, seven showed abnormal soft markers or structures in ultrasound and three of the seven pedigrees had high risk of fetal trisomy 18. Conclusions Ultrasound screening is highly sensitive in detecting rec(18) fetuses, yet the association between ultrasound features and fetal karyotypes is not clear. The combination of multiple genetic analysis methods, including karyotype analysis, CMA and FISH, may be conducive to clarifying the types and sources of complex derived chromosomes. Key words: Chromosomes, human, pair 18; Chromosome inversion; Ultrasonography, prenatal; Genetic counseling

Pericentric inversion of chromosome 7 in human being associated with recurrent ICSI failure: A case report

Assisted reproductive techniques is specially a boon for severe male factor infertility with non-obstructive azoospermia (NOAZ) and severe oligospermia ( less than 5 million/ml). To study the unusual pericentric inversion in a recurrent ICSI failure case, cytogenetic analysis was done from peripheral blood lymphocytes. Semen analysis revealed that the man had Oligoasthenoteratozoospermia with sperm count of 0.9 million/ml. A karyogram revealed pericentromeric inversion of Chromosome 7. It could be accommodated on models that location of the breakpoint harbours critical genes for spermatogenesis (swm, swm2 and STAG3). Pericentromeric Inversion for chromosome 7 is a rare finding. It may be the etiopathogenic for partial spermatogenetic arrest and recurrent ICSI failure. The children born to such couples must also be analyzed and kept under observation for any clinical indications.

Pericentric Inversion of Chromosome 1 in a Child with Low Height: Diagnostic Dilemmas

The inversions are one of the most common chromosomal abnormalities. They occur when two breaks occur in a chromosome; the segment as well originated is reversed and becomes the reintegration on the same chromosome. Generally, an inversion does not cause an abnormal phenotype in the carrier, but it can do so in their offspring. Which sometimes can be associated with cases of mental retardation, congenital malformations or infertility. It is critical to determine if the inversion has a family origin, where there usually is no risks for the individual, or if it is a de novo mutation, the risk is somewhat higher, possibly due to the interruption of a key sequence of the gene. The pericentric inversion of chromosome 1 is one of the structural chromosomal variations that are not common, and it has been observed in general population and patients with abnormal phenotypes and disease. We report the case of a child that came to the office for presenting a failure to thrive every year; the cytogenetic testing reported an inversion of chromosome 1 without maternal origin nor paternal. In this case, there is no evidence that low height has relation with the abnormal chromosome.

Preimplantation genetic diagnosis of X-linked Charcot-Marie-Tooth disease by indirect linkage analysis

ObjectiveTo present methodical approach of preimplantation genetic diagnosis (PGD) as an option for an unaffected pregnancy in reproductive-age couples who have a genetic risk of the X-linked dominant peripheral neuropathy Charcot-Marie-Tooth type 1 disease. Patients and methodsWe performed PGD of X-linked Charcot-Marie-Tooth type 1 disease using haplotyping/indirect linkage analysis, when during analysis we reach to exclude embryos that carry a high-risk haplotype linked to the causal mutation p.Leu9Phe in the GJB1 gene. ResultsWithin the PGD cycle, we examined 4 blastomeres biopsied from cleavage-stage embryos and recommended 3 embryos for transfer. Two embryos were implanted into the uterus; however, it resulted in a singleton pregnancy with a male descendant. Three years later, the couple returned again with spontaneous gravidity. A chorionic biopsy examination of this gravidity ascertained the female sex and a pericentric inversion of chromosome 5 in 70% of the cultivated foetal cells. ConclusionUsing indirect linkage analysis, PGD may help to identify genetic X-linked defects within embryos during screening, thereby circumventing the potential problems with abortion.