Prenatal diagnosis of a trisomy 7 mosaic case: CMA, CNV-seq, karyotyping, interphase FISH, and MS-MLPA, which technique to choose?

OBJECTIVE: This study aims to perform a prenatal genetic diagnosis of a high-risk fetus with trisomy 7 identified by noninvasive prenatal testing (NIPT) and to evaluate the efficacy of different genetic testing techniques for prenatal diagnosis of trisomy mosaicism. METHODS: For prenatal diagnosis of a pregnant woman with a high risk of trisomy 7 suggested by NIPT, karyotyping and chromosomal microarray analysis (CMA) were performed on an amniotic fluid sample. Low-depth whole-genome copy number variation sequencing (CNV-seq) and fluorescence in situ hybridization (FISH) were used to clarify the results further. In addition, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was performed to analyze the possibility of uniparental disomy(UPD). RESULTS: Amniotic fluid karyotype analysis revealed a 46, XX result. Approximately 20% mosaic trisomy 7 was detected according to the CMA result. About 16% and 4% of mosaicism was detected by CNV-seq and FISH, respectively. MS-MLPA showed no methylation abnormalities. The fetal ultrasound did not show any detectable abnormalities except for mild intrauterine growth retardation seen at 39 weeks of gestation. After receiving genetic counseling, the expectant mother decided to continue the pregnancy, and follow-up within three months of delivery was normal. CONCLUSION: In high-risk NIPT diagnosis, a combination of cytogenetic and molecular genetic techniques proves fruitful in detecting low-level mosaicism. Furthermore, the exclusion of UPD on chromosome 7 remains crucial when NIPT indicates a positive prenatal diagnosis of trisomy 7.

Phenotypic variability and management of patients with mosaic monosomy X and Y chromosome material: a case series.

BACKGROUND: we aim to discuss the origin and the differences of the phenotypic features and the management care of rare form of disorder of sex development due to Mosaic monosomy X and Y chromosome materiel. METHODS: We report our experience with patients harboring mosaic monosomy X and Y chromosome material diagnosed by blood cells karyotypes and cared for in our department from 2005 to 2022. RESULTS: We have included five infants in our study. The current average age was 8 years. In four cases, the diagnosis was still after born and it was at the age of 15 years in one case. Physical examination revealed a variable degree of virilization, ranging from a normal male phallus with unilateral ectopic gonad to ambiguous with a genital tubercle and bilateral not palpable gonads in four cases and normal female external genitalia in patient 5. Karyotype found 45, X/46, XY mosaicism in patient 1 and 2 and 45, X/46, X, der (Y) mosaicism in patient 3, 4 and 5. Three cases were assigned to male gender and two cases were assigned to female. After radiologic and histologic exploration, four patients had been explored by laparoscopy to perform gonadectomy in two cases and Mullerian derivative resection in the other. Urethroplasty was done in two cases of posterior hypospadias. Gender identity was concordant with the sex of assignment at birth in only 3 cases. CONCLUSION: Because of the phenotypic heterogeneity of this sexual disorders and the variability of its management care, then the decision should rely on a multidisciplinary team approach.

Establishment and partial characterisation of a new cell line derived from adult tissues of the tsetse fly Glossina morsitans morsitans.

BACKGROUND: Insect cell lines play a vital role in many aspects of research on disease vectors and agricultural pests. The tsetse fly Glossina morsitans morsitans is an important vector of salivarian trypanosomes in sub-Saharan Africa and, as such, is a major constraint on human health and agricultural development in the region. METHODS: Here, we report establishment and partial characterisation of a cell line, GMA/LULS61, derived from tissues of adult female G. m. morsitans. GMA/LULS61 cells, grown at 28 °C in L-15 (Leibovitz) medium supplemented with foetal bovine serum and tryptose phosphate broth, have been taken through 23 passages to date and can be split 1:1 at 2-week intervals. Karyotyping at passage 17 revealed a predominantly haploid chromosome complement. Species origin and absence of contaminating bacteria were confirmed by PCR amplification and sequencing of fragments of the COI gene and pan-bacterial 16S rRNA gene respectively. However, PCR screening of RNA extracted from GMA/LULS61 cells confirmed presence of the recently described Glossina morsitans morsitans iflavirus and Glossina morsitans morsitans negevirus, but absence of Glossina pallipides salivary gland hypertrophy virus. GMA/LULS61 cells supported infection and growth of 6/7 different insect-derived strains of the intracellular bacterial symbiont Wolbachia. CONCLUSIONS: The GMA/LULS61 cell line has potential for application in a variety of studies investigating the biology of G. m. morsitans and its associated pathogenic and symbiotic microorganisms.

Prenatal diagnosis of fetuses with absent/hypoplastic nasal bone in second-trimester using chromosomal microarray analysis.

BACKGROUND: Pathogenic copy number variants (pCNVs) are associated with fetal ultrasound anomalies, which can be efficiently identified through chromosomal microarray analysis (CMA). The primary objective of the present study was to enhance understanding of the genotype-phenotype correlation in fetuses exhibiting absent or hypoplastic nasal bones using CMA. METHODS: Enrolled in the present study were 94 cases of fetuses with absent/hypoplastic nasal bone, which were divided into an isolated absent/hypoplastic nasal bone group (n = 49) and a non-isolated group (n = 45). All pregnant women enrolled in the study underwent karyotype analysis and CMA to assess chromosomal abnormalities in the fetuses. RESULTS: Karyotype analysis and CMA detection were successfully performed in all cases. The results of karyotype and CMA indicate the presence of 11 cases of chromosome aneuploidy, with trisomy 21 being the most prevalent among them. A small supernumerary marker chromosome (sSMC) detected by karyotype analysis was further interpreted as a pCNV by CMA. Additionally, CMA detection elicited three cases of pCNVs, despite normal findings in their karyotype analysis results. Among them, one case of Roche translocation was identified to be a UPD in chromosome 15 with a low proportion of trisomy 15. Further, a significant difference in the detection rate of pCNVs was observed between non-isolated and isolated absent/hypoplastic nasal bone (24.44% vs. 8.16%, p < .05). CONCLUSION: The present study enhances the utility of CMA in diagnosing the etiology of absent or hypoplastic nasal bone in fetuses. Further, isolated cases of absent or hypoplastic nasal bone strongly suggest the presence of chromosomal abnormalities, necessitating genetic evaluation through CMA.

A multiomic characterization of the leukemia cell line REH using short- and long-read sequencing.

The B-cell acute lymphoblastic leukemia (ALL) cell line REH, with the t(12;21) ETV6::RUNX1 translocation, is known to have a complex karyotype defined by a series of large-scale chromosomal rearrangements. Taken from a 15-yr-old at relapse, the cell line offers a practical model for the study of pediatric B-ALL. In recent years, short- and long-read DNA and RNA sequencing have emerged as a complement to karyotyping techniques in the resolution of structural variants in an oncological context. Here, we explore the integration of long-read PacBio and Oxford Nanopore whole-genome sequencing, IsoSeq RNA sequencing, and short-read Illumina sequencing to create a detailed genomic and transcriptomic characterization of the REH cell line. Whole-genome sequencing clarified the molecular traits of disrupted ALL-associated genes including CDKN2A, PAX5, BTG1, VPREB1, and TBL1XR1, as well as the glucocorticoid receptor NR3C1 Meanwhile, transcriptome sequencing identified seven fusion genes within the genomic breakpoints. Together, our extensive whole-genome investigation makes high-quality open-source data available to the leukemia genomics community.

Chromosome analysis of 303 pregnancy losses in Mexico.

BACKGROUND: Chromosomal abnormalities are present in 50 to 60% of miscarriages and in 6 to 19% of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology. OBJECTIVE: To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age. MATERIAL AND METHODS: Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample. RESULTS: In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7%; that of single nucleotide polymorphism microarrays, 94.5%; and that of fluorescence in situ hybridization and short tandem repeat, 100%. Cytogenetic abnormalities were observed in 57.6% of miscarriages and in 24.5% of stillbirths; 94% of total anomalies were numerical and 6% were submicroscopic. CONCLUSIONS: Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.

ANTECEDENTES: Las alteraciones cromosómicas están presentes en 50 a 60 % de los abortos espontáneos y en 6 a 19 % de los mortinatos. Aunque se prefieren los microarreglos para estudiarlos, numerosos hospitales no pueden ofrecerlos. OBJETIVO: Presentar los resultados del estudio citogenético de 303 productos de la concepción (POC), 184 se obtuvieron de abortos espontáneos, 49 fueron mortinatos y en 17 no se identificó la de edad gestacional. MATERIAL Y MÉTODOS: Se empleó cariotipo, hibridación in situ con fluorescencia, secuencias cortas repetidas en tándem y microarreglos, según el tipo de pérdida y la muestra disponible. RESULTADOS: En 29 POC se encontró tejido materno, por lo que fueron eliminados de los análisis. En 250 (91.2 %)/274 casos se obtuvieron resultados informativos; la tasa de éxito del cariotipo fue de 80.7 %; la de los microarreglos de SNP, de 94.5 %; y la de la hibridación fluorescente in situ y la repetición corta en tándem, de 100 %. Se observaron anomalías citogenéticas en 57.6 % de los abortos espontáneos y en 24.5 % de los mortinatos; 94 % de las anomalías fueron numéricas y 6 %, submicroscópicas. CONCLUSIONES: El cariotipo en conjunto con el estudio de secuencias cortas repetidas en tándem para descartar contaminación de células maternas es efectivo para estudiar abortos espontáneos; los microarreglos se recomiendan en los mortinatos.

Primary amenorrhoea - cytogenetic study in 40 Indian women.

BACKGROUND: Primary amenorrhoea (PA) refers to an ailment when adolescent girls do not attain menarche naturally. It is one of the most common gynaecological disorders specified. Chromosomal abnormalities play a pivotal role in PA. Cytogenetic analysis is an indispensable diagnostic tool to determine the abnormality of the chromosome. In an emerging country like India, cytogenetic analysis is at a nascent stage. There are very few studies on Cytogenetics present in eastern India, including West Bengal. In rural and suburban areas PA sufferers often experience late diagnosis and struggle to access suitable curative management. The aim of the study is to evaluate the various types of chromosomal abnormalities in patients suffering from PA for accurate, better management of the same and further counselling. METHODS: A total of 40 PA cases were referred by obstetricians and gynaecologists to the Department of Genetics of Nirnayan Health Care, Kolkata. To screen the chromosomal abnormalities, human leukocyte culture was accomplished with their peripheral venous blood followed by G-banding and then karyotyping was executed according to ISCN-2020. RESULT: Out of 40 patients, 29 were normal among which 46,XX was found in 70% cases (n = 28) and 46,XX,9qh + in 2.5% (n = 1). The remaining 11 showed different types of abnormalities. 45,X was found in 10% (n = 4), 46,X,i(X)(q10) in 2.5% (n = 1), 46,X,del(X)(p11.2) in 2.5% (n = 1), 46,X,del(X)(p22.1) in 2.5% (n = 1), 46,X,del(X)(q24) in 2.5% (n = 1), 46,XY in 2.5% (n = 1), mos 45,X[22]/46,Xi(X)(q.10)[8] in 2.5% (n = 1) and mos 45,X[16]/46,XY[14] (2.5%) in 2.5% (n = 1). CONCLUSION: This study indicates the importance of chromosomal study which must be included in early diagnosis of PA. Karyotyping at the appropriate phase of life will not only help in the judicial management of this disorder but will also give young girls a better lifestyle.

Primary amenorrhoea is a common gynecological disorder reported in adolescent girls, often linked to chromosomal abnormalities. In Eastern India, including West Bengal, where cytogenetic analysis is still in its nascent stage, late diagnosis and limited access to curative management are prevalent issues. A study conducted from January 2021 to May 2023 at Nirnayan Healthcare, Kolkata aimed to evaluate chromosomal abnormalities in 40 PA cases. Out of these, 28 exhibited normal karyotypes (46,XX); one patient was reported with 46,XX,9qh + which is considered a normal karyotype, while the remaining 11 revealed diverse abnormalities, including 45,X; sex reversal & several structural variations. The study underscores the significance of cytogenetic analysis in the early diagnosis of Primary Amenorrhoea. Early karyotyping not only facilitates judicious management but also ensures a better lifestyle for affected girls.

Optical Genome Mapping as a New Tool to Overcome Conventional Cytogenetics Limitations in Patients with Bone Marrow Failure.

Cytogenetic studies are essential in the diagnosis and follow up of patients with bone marrow failure syndromes (BMFSs), but obtaining good quality results is often challenging due to hypocellularity. Optical Genome Mapping (OGM), a novel technology capable of detecting most types chromosomal structural variants (SVs) at high resolution, is being increasingly used in many settings, including hematologic malignancies. Herein, we compared conventional cytogenetic techniques to OGM in 20 patients with diverse BMFSs. Twenty metaphases for the karyotype were only obtained in three subjects (15%), and no SVs were found in any of the samples. One patient with culture failure showed a gain in chromosome 1q by fluorescence in situ hybridization, which was confirmed by OGM. In contrast, OGM provided good quality results in all subjects, and SVs were detected in 14 of them (70%), mostly corresponding to cryptic submicroscopic alterations not observed by standard techniques. Therefore, OGM emerges as a powerful tool that provides complete and evaluable results in hypocellular BMFSs, reducing multiple tests into a single assay and overcoming some of the main limitations of conventional techniques. Furthermore, in addition to confirming the abnormalities detected by conventional techniques, OGM found new alterations beyond their detection limits.

Karyotype Description and Comparative Chromosomal Mapping of 5S rDNA in 42 Species.

This study was conducted to evaluate the 5S rDNA site number, position, and origin of signal pattern diversity in 42 plant species using fluorescence in situ hybridization. The species were selected based on the discovery of karyotype rearrangement, or because 5S rDNA had not yet been explored the species. The chromosome number varied from 14 to 160, and the chromosome length ranged from 0.63 to 6.88 µm, with 21 species having small chromosomes (<3 µm). The chromosome numbers of three species and the 5S rDNA loci of nineteen species are reported for the first time. Six 5S rDNA signal pattern types were identified. The 5S rDNA varied and was abundant in signal site numbers (2-18), positions (distal, proximal, outside of chromosome arms), and even in signal intensity. Variation in the numbers and locations of 5S rDNA was observed in 20 species, whereas an extensive stable number and location of 5S rDNA was found in 22 species. The potential origin of the signal pattern diversity was proposed and discussed. These data characterized the variability of 5S rDNA within the karyotypes of the 42 species that exhibited chromosomal rearrangements and provided anchor points for genetic physical maps.

Low-level mosaic trisomy 21 at amniocentesis and cordocentesis in the second trimester in a pregnancy associated with positive non-invasive prenatal testing for trisomy 21, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis and cordocentesis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 26-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of positive non-invasive prenatal testing (NIPT) for trisomy 21 at 16 weeks of gestation. Amniocentesis revealed a karyotype of 47,XX,+21[3]/46,XX[17], and multiplex ligation-dependent probe amplification (MLPA) on uncultured amniocytes revealed rsa X(P095) × 2, (13, 18, 21) × 2. She underwent cordocentesis (cord blood sampling) at 21 weeks of gestation which revealed a karyotype of 47,XX,+21[2]/46,XX[48]. At 27 weeks of gestation, she was referred to our hospital for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XX in 20/20 colonies. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (1-22,X) × 2, Y × 0 with no genomic imbalance. Interphase fluorescence in situ hybridization (FISH) analysis on 104 uncultured amniocytes detected one cell (1/104 = 0.9%) with trisomy 21, while the rest cells were disomy 21, compared with 0% (0/100) in the normal control. The woman was encouraged to continue the pregnancy. The pregnancy was carried to 38 weeks of gestation, and a 2771-g female baby was delivered no phenotypic abnormality. aCGH analysis on the cord blood showed arr (1-22,X) × 2, Y × 0 with no genomic imbalance. The umbilical cord had a karyotype of 47,XX,+21[3]/46,XX[37]. The placenta had a karyotype of 46,XX. When follow-up at age 3½ months, the neonate was phenotypically normal and had normal development. The peripheral blood had a karyotype of 46,XX in 40/40 cells. Interphase FISH analysis on buccal mucosal cells detected normal disomy 21 cells in 100/100 cells. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis and cordocentesis in the second trimester can be associated with perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

Low-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis in a pregnancy with a favorable fetal outcome. CASE REPORT: A 38-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XY,+21[4]/46,XY[34]. Prenatal ultrasound findings were normal. At 27 weeks of gestation, she was referred for genetic counseling, and the cultured amniocytes had a karyotype of 47,XY,+21[2]/46,XY[26]. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21. Interphase fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes revealed 30% (30/100 cells) mosaicism for trisomy 21. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 21q11.2q22.3 × 2.25, consistent with 20%-30% mosaicism for trisomy 21. The parental karyotypes were normal. The woman was advised to continue the pregnancy, and a 3510-g phenotypically normal male baby was delivered at 39 weeks of gestation. Cytogenetic analysis of the cord blood, umbilical cord and placenta revealed the karyotypes of 47,XY,+21[1]/46,XY[39], 47,XY,+21[2]/46,XY[38] and 46,XY in 40/40 cells, respectively. When follow-up at age 1 year and 2 months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY in 40/40 cells, and interphase FISH analysis on uncultured buccal mucosal cells showed 6.4% (7/109 cells) mosaicism for trisomy 21. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

Mosaic distal 10q deletion or 46,XY,del(10) (q26.13)/46,XY at amniocentesis and cordocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

OBJECTIVE: We present mosaic distal 10q deletion at prenatal diagnosis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 40-year-old, gravida 2, para 0, woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY, del(10) (q26.13)[6]/46,XY[17]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed 35% mosaicism for the 10q26.13q26.3 deletion. At 22 weeks of gestation, she underwent cordocentesis which revealed a karyotype of 46,XY,del(10) (q26.13)[16]/46,XY[24]. Prenatal ultrasound findings were normal. At 24 weeks of gestation, she was referred for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XY,del(10) (q26.13)[4]/46,XY[22]. The parental karyotypes were normal. Molecular genetic analysis on uncultured amniocytes revealed no uniparental disomy (UPD) 10 by quantitative fluorescence polymerase chain reaction (QF-PCR), arr 10q26.13q26.3 × 1.6 (40% mosaicism) by aCGH, and 29.8% (31/104 cells) mosaicism for the distal 10q deletion by interphase fluorescence in situ hybridization (FISH). The woman was advised to continue the pregnancy, and a phenotypically normal 2,900-g male baby was delivered at 39 weeks of gestation. The cord blood had a karyotype of 46,XY,del(10) (q26.13)[6]/46,XY[34], and both the umbilical cord and the placenta had the karyotype of 46,XY. When follow-up at age four months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY,del(10) (q26.13)[5]/46,XY[35], and interphase FISH analysis on buccal mucosal cells showed 8% (8/102 cells) mosaicism for distal 10q deletion. CONCLUSION: Mosaic distal 10q deletion with a normal cell line at prenatal diagnosis can be associated with a favorable fetal outcome and perinatal progressive decrease of the aneuploid cell line.

Clinical course and genetic analysis of a case of the amniocentesis showing chromosome 6 trisomy mosaicism.

OBJECTIVE: Herein, we present a case of mosaic trisomy 6 detected by amniocentesis. CASE REPORT: Amniocentesis (G-banding) was performed at 17 weeks of gestation; the results were 47,XY,+6[3]/46,XY[12]. Fetal screening ultrasonography showed no morphological abnormalities, and the parents desired to continue the pregnancy. The infant was delivered vaginally at 39 weeks' gestation. The male infant weighed 3002 g at birth with no morphological abnormalities. G-banding karyotype analysis performed on the infant's peripheral blood revealed 46,XY[20]. FISH analysis revealed trisomy signals on chromosome 6 in 1-4 out of 100 cells from the placenta. The single nucleotide polymorphism microarray of the umbilical cord blood revealed no abnormalities. Methylation analysis of umbilical cord blood revealed no abnormalities in PLAGL1. No disorders were observed at one year of age. CONCLUSION: When amniocentesis reveals chromosomal mosaicism, it is essential to provide a thorough fetal ultrasound examination and careful genetic counseling to support the couples' decision-making.

Identification of Novel NSD1 variations in four Pediatric cases with sotos Syndrome.

OBJECTIVE: Sotos syndrome (SOTOS) is an uncommon genetic condition that manifests itself with the following distinctive features: prenatal overgrowth, facial abnormalities, and intellectual disability. This disorder is often associated with haploinsufficiency of the nuclear receptor-binding SET domain protein 1 (NSD1)gene. We investigated four pediatric cases characterized by early-onset overgrowth and developmental delay. The primary objective of this study was to achieve accurate genetic diagnoses. DESIGN&METHODS: A sequential analysis approach comprising chromosomal karyotyping, whole exome sequencing, and microarray analysis was conducted. RESULTS: All four cases exhibited variations in the NSD1 gene, with the identification of four previously unreported de novo variants, each specific to one case.Specifically, Case 1 carried the NSD1 (NM_022455): c.2686 C > T(p.Q896X) variant, Case 2 had the NSD1 (NM_022455): c.2858_2859delCT(p.S953X) variant, Case 3 displayed a chromosomal aberration, chr5: 5q35.2q35.3(176,516,604-176,639,249)×1, which encompassed the 5'-untranslated region of NSD1, and Case 4 harbored the NSD1 (NM_022455): c.6397T > G(p.C2133G) variant. CONCLUSION: This study not only provided precise diagnoses for these cases but also supplied significant evidence to facilitate informed consultations. Furthermore, our findings expanded the spectrum of mutations associated with SOTOS.

[Genetic analysis and assisted reproductive guidance for two infertile patients with rare small supernumerary marker chromosomes].

OBJECTIVE: To carry out cytogenetic and molecular genetic analysis for two infertile patients carrying rare small supernumerary marker chromosomes (sSMC). METHODS: Two infertile patients who received reproductive and genetic counseling at CITIC Xiangya Reproductive and Genetic Hospital on October 31, 2018 and May 10, 2021, respectively were selected as the study subjects. The origin of sSMCs was determined by conventional G banding, fluorescence in situ hybridization (FISH) and copy number variation sequencing (CNV-seq). Microdissection combined with high-throughput whole genome sequencing (MicroSeq) was carried out to determine the fragment size and genomic information of their sSMCs. RESULTS: For patient 1, G-banded karyotyping and FISH revealed that he has a karyotype of mos47,XY,del(16)(p10p12),+mar[65]/46,XY,del(16)(p10p12)[6]/48,XY,del(16)(p10p12),+2mar[3].ish mar(Tel 16p-,Tel 16q-,CEP 16-,WCP 16+). CNV analysis has yielded a result of arr[GRCh37]16p12.1p11.2(24999364_33597595)×1[0.25]. MicroSeq revealed that his sSMC has contained the region of chromosome 16 between 24979733 and 34023115 (GRCh37). For patient 2, karyotyping and reverse FISH revealed that she has a karyotype of mos 47,XX,+mar[37]/46,XX[23].rev ish CEN5, and CNV analysis has yielded a result of seq[GRCh37]dup(5)(p12q11.2)chr5:g(45120001_56000000)dup[0.8]. MicroSeq results revealed that her sSMC has contained the region of chromosome 5 between 45132364 and 55967870(GRCh37). After genetic counseling, both couples had opted in vitro fertilization (IVF) treatment and preimplantation genetic testing (PGT). CONCLUSION: For individuals harboring sSMCs, it is vital to delineate the origin and structural characteristics of the sSMCs for their genetic counseling and reproductive guidance. Preimplantation genetic testing after microdissection combined with high-throughput whole genome sequencing (MicroSeq-PGT) can provide an alternative treatment for carrier couples with a high genetic risk.

[Frequency and characteristics of Y chromosome microdeletions and karyotypic abnormalities among 4 278 infertile male patients from southwest China].

OBJECTIVE: To determine the frequency and characteristics of AZF microdeletions of Y chromosome and karyotypic abnormalities among infertile male patients from southwest China. METHODS: 4 278 infertile male patients treated at West China Second University Hospital of Sichuan University from September 2018 to July 2023 were selected as the study subjects. Results of Y chromosome microdeletion detection and G-banded karyotyping analysis were retrospectively reviewed. RESULTS: Clinical data of the patients were collected, which have included 2 048 patients with azoospermia, 1 536 patients with oligozoospermia, 310 patients with mild to moderate oligozoospermia, and 384 patients with infertility but normal sperm concentration. An abnormal karyotype was found in 213 (8.80%) of 2 421 patients who had undergone karyotyping analysis. The frequency of Y chromosome microdeletions was 9.86% (422/4 278), which had occurred in 10.4%, 13.28%, 0.97% and 0.52% of the cases with azoospermia, severe oligozoospermia, mild to moderate oligozoospermia, and infertility with normal sperm concentration, respectively. CONCLUSION: Y chromosome microdeletion detection and karyotyping analysis are crucial for assessing the cause of male infertility. Early diagnosis can facilitate the selection of reproductive methods.

[Prenatal diagnosis of a fetus with 1p36 deletion syndrome and 3p26.3p25.2 duplication].

OBJECTIVE: To explore the characteristics of a fetus with chromosome 1p36 deletion syndrome and 3p26.3p25.2 duplication. METHODS: A pregnant woman who had attended the Genetic Counseling Clinic of Linyi People's Hospital on February 22, 2022 and her fetus were selected as the study subjects. Clinical data were collected. Chromosomal karyotyping, fluorescence in situ hybridization (FISH) and chromosomal microarray analysis (CMA) were carried out for the prenatal diagnosis. RESULTS: Ultrasonography at 24th gestational week revealed that the fetus had ventricular septal defect, single umbilical artery, and slight widening of left lateral ventricle (12 mm). The woman was found to have a karyotype of 46,XX,t(1;3)(p36.22;p25.2), and the result of FISH was t(1;3)(3pter+,1qter+;1pter+,3qter+). The fetus was found to have a karyotype of 46,X?,add(1)(p36), and CMA confirmed that it has a 9.0 Mb deletion at 1p36.33p36.22 and a 12.6 Mb duplication at 3p26.3p25.2. Combining the maternal karyotype, the molecular karyotype of the fetus was determined as 46,X?,der(1)t(1;3)(p36.22;p25.2)mat.arr[hg19]1p36.33p36.22(849467_9882666)×1, 3p26.3p25.2(61892_12699607)×3, with the former known to be associated with 1p36 deletion syndrome. CONCLUSION: The fetus was diagnosed with 1p36 deletion syndrome, and its 1p36.33p36.22 deletion and 3p26.3p25.2 duplication had both derived from the balanced translocation carried by its mother.

[Genetic analysis for a female carrying idic(Y)(p11.32) with Disorders of sex development].

OBJECTIVE: To explore the genetic basis for a patient with Disorders of sex development (DSD). METHODS: A female patient who had presented at the Linyi People's Hospital due to primary amenorrhea on April 6, 2022 was selected as the study subject. Conventional chromosomal karyotyping, fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), fluorescence quantitative PCR and Sanger sequencing were carried out for the patient. RESULTS: The patient, a 14-year-old female, had featured short statue, multiple nevi, and primary amenorrhea. She was found to have a karyotype of 46,X,idic(Y)(p11.3)[59]/45,X[39]/47,X,idic(Y)(p11.3)×2[2]. The result of FISH assay was 46,X,der(Y).ish idic(Y)(p11.3)(SRY+)[59]/45,X[39]/47,X,der(Y)×2.ish idic(Y)(p11.3)(SRY+)[2]. That of CMA was arr[GRCh37](X)×1,(Y)×0-1,arr[GRCh37]Yp11.32(118552_472090)×1. The patient had no deletion in the AZF region of Y chromosome, and was negative for variant of SRY gene. Combining the above results, her molecular karyotype was determined as mos 46,X,idic(Y)(p11.32)[59]/45,X[39]/47,X,idic(Y)(p11.32)×2[2].ish 46,X,idic(Y)(p11.32)(DXZ1+,DYZ1++,DYZ3++,SRY+)[59]/45,X(DXZ1+,DYZ1-,DYZ3-,SRY-)[39]/47,X,der(Y)×2.ish idic(Y)(p11.32)(DXZ1+,DYZ1++,DYZ3++,SRY+)[2].arr[GRCh37](X)×1, (Y)×0-1，arr[GRCh37]Yp11.32(118552_472090)×1. The patient was diagnosed with mosaicism DSD with idic(Y)(p11.32). CONCLUSION: The abnormal mosaicism karyotype probably underlay the DSD in this patient.

[Genetic analysis of a fetus with Pitt-Hopkins syndrome due to a 18q21.2q21.31 microdeletion].

OBJECTIVE: To carry out invasive prenatal diagnosis for a fetus with ultrasound-indicated agenesis of corpus callosum and explore its genetic etiology. METHODS: A pregnant woman presented at the Affiliated Hospital of Putian College on December 16, 2022 was selected as the study subject. Amniotic fluid and peripheral blood samples from the fetus and the couple were collected. Conventional G-banded chromosomal karyotyping was carried out, and whole-genome copy number variation analysis was performed using single nucleotide polymorphism microarray (SNP-array). RESULTS: The karyotypes of the fetus and the couple were normal by the G-banding analysis. SNP-array analysis of the amniotic fluid sample revealed a 4.5 Mb microdeletion in the 18q21.2q21.31 region of the fetus. SNP-array analysis of peripheral blood samples from the couple did not find any abnormality. CONCLUSION: Through G-banded chromosomal karyotyping and SNP-array analysis, a fetus with 18q21.2q21.31 microdeletion was identified, which has conformed to the diagnosis of Pitt-Hopkins syndrome. Above finding has provided a basis for genetic counseling for the couple.

Revisiting Atrioventricular Septal Defects: Exploring Chromosomal Abnormalities, Cardiac and Extracardiac Anomalies in a Contemporary Prenatal Cohort.

To estimate if there is an association between partial AVSD with chromosomal abnormalities, cardiac and extracardiac malformations, and to report the outcomes of prenatally diagnosed AVSD in a large, contemporary cohort. This is a retrospective cohort study of 190 prenatally diagnosed fetal AVSD between 2014 and 2023. Type of AVSD (complete vs partial), additional cardiac findings, extracardiac findings, presence of a heterotaxy, results of prenatal karyotype, and pregnancy outcomes were documented and analyzed. A total of 190 cases of fetal AVSD were analyzed. Complete AVSDs comprised 141 (74.2%) of the cohort, while partial AVSDs comprised 49 (25.7%). Karyotype was completed in 131 cases, and in 98 (74.8%) cases chromosomal abnormalities were identified, with trisomy 21 being the most common (53/131, 40.5%). Complete AVSDs were associated with trisomy 21 (45.5%, p = 0.04), Isolated cases of complete AVSDs (p = 0.03). Partial AVSDs were associated with trisomy 18 (53.1%, p < 0.001). In cases of partial AVSDs with aneuploidies, 7 (70%) had an ostium primum defect and 20 (90.9%) of AV canal type VSD. Isolated partial AVSD had no clear association with aneuploidies. There were additional cardiac anomalies in 96 (50.5%) and extracardiac anomalies in 134 (70.5%) of the cohort. There were no differences between partial and complete AVSD in rate of additional cardiac and extracardiac anomalies. AVSD was part of a heterotaxy in 47 (24.7%) of cases, and heterotaxy was associated with complete AVSD in the majority of cases (43/47, 91.4%, p = 0.003). Fetal partial AVSDs are associated with trisomy 18. Fetal complete AVSDs, even isolated, are associated with trisomy 21. There were no differences in association of other aneuploidies, additional cardiac findings, or extracardiac anomalies between prenatally diagnosed complete AVSDs and partial AVSDs.