OBJECTIVE: Chromosome conformation-based karyotype analysis (C-MoKa) technology was used to test a couple who had experienced multiple adverse pregnancies in order to provide them with genetic counseling and reproductive guidance. METHODS: A couple presented at the Reproductive Medicine Center of the First Hospital of Lanzhou University in 2023 was selected as the study subject. Through C-MoKa testing, copy number variation sequencing (CNV-seq), and preimplantation genetic testing for aneuploidy (PGT-A), it was found that the couple's repeatedly miscarried fetuses and abnormal embryos exhibited highly similar chromosomal structural abnormalities. Using C-MoKa, the potential genetic abnormalities in both partners were traced, and reproductive guidance was provided based on the result. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: LDYYSZLLKH2025-09). RESULTS: CNV-seq analysis of the couple's miscarriage fetal chorionic villi showed del(18)(q21.2q23)(28.90 Mb) and dup(13)(q31.2q34)(26.26 Mb). Chromosomal karyotyping analysis of both partners showed no abnormality. From 2024 to 2025, the couple underwent three rounds of PGT-A assisted reproduction. The first embryo test showed del(13)(q31.2q34)(26.77 Mb) and dup(18)(q21.2q23)(29.08 Mb). The second embryo test showed dup(13)(q31.2q34)(26.26 Mb) and del(18)(q21.2q23)(28.90 Mb). And the third embryo test results showed complex chromosomal abnormalities. In 2025, after genetic counseling, the couple had opted C-MoKa test, which has detected no abnormality in the wife, but a balanced 46,XY,t(13;18)(q31.2;q21.2) translocation in the husband. CONCLUSION As a high-throughput sequencing method based on the three-dimensional conformation of chromatin, C-MoKa has the advantages of high resolution and high accuracy, and can accurately detect balanced translocations with similar banding patterns. It has therefore offered a powerful new tool for chromosomal analysis.
Female ; Humans ; Male ; Pregnancy ; Abortion, Habitual/genetics* ; DNA Copy Number Variations ; Karyotyping/methods* ; Preimplantation Diagnosis ; Translocation, Genetic

OBJECTIVE: To investigate the genetic mechanism for adverse pregnancies due to submicroscopic chromosomal structural variants in two cases, and to provide a precise guidance for preimplantation genetic testing. METHODS: Two families who had visited Chengdu Women's and Children's Central Hospital for reproduction guidance due to recurrent miscarriages, adverse pregnancy history and abnormal genetic testing of the offspring in June and December 2023 were selected as the study subjects. Chromosomal karyotyping and optical genome mapping (OGM) were carried out on peripheral blood samples from the two couples, and preimplantation genetic testing for structural rearrangement (PGT-SR) were performed on the blastocyst trophoblasts. This study was approved by the Medical Ethics Committee of the Hospital (Ethic No.: 2023-23). RESULTS: No abnormality was found on the G-banded karyotyping analysis for both couples. The OGM results revealed that the female partner of couple 1 had a translocation between 4pter-p16.3 (3.99 Mb) and 11pter-p15.4 (2.66 Mb), whilst no abnormality was found in the male partner. Similarly, the male partner of couple 2 had a translocation between 19q13.43-qter (1.90 Mb) and 22q13.31-qter (3.34 Mb). No abnormality was found in the female partner of couple 2. Neither breakpoints nor the adjacent region had involved an OMIM gene, except the formation of a fusion gene ZIM2-AS1-Z82186.1 (Both genes are non-coding, and the fusion gene was deemed as variant of unknown significance). PGT-SR of 11 blastocysts derived from couple 1 revealed that one embryo was suitable for priority transfer, three embryos were suitable for transfer, one embryo was recommended for genetic counselling, and six embryos were unsuitable for the transfer. For couple 2, six blastocysts were tested, of which only one embryo was deemed suitable for transfer. CONCLUSION When genetic testing of offspring indicates copy number variations such as deletions, duplications or mosaicism, the high-resolution OGM technique can be selected to screen parents for submicroscopic chromosomal structural variations. The result can facilitate accurate assessment for the risk of recurrence in offspring, selection of suitable method for reproduction, and identifying targets for PGT.
Humans ; Female ; Pregnancy ; Adult ; Male ; Karyotyping ; Chromosome Aberrations ; Abortion, Habitual/genetics* ; Preimplantation Diagnosis ; Genetic Testing

OBJECTIVE: To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention. METHODS: Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010). RESULTS: In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born. CONCLUSION This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans ; Female ; Male ; Pedigree ; Exostoses, Multiple Hereditary/diagnosis* ; N-Acetylglucosaminyltransferases/genetics* ; Adult ; Exostosin 1 ; Asian People/genetics* ; Genetic Testing ; Exostosin 2 ; Mutation ; China ; Prenatal Diagnosis ; Pregnancy ; Genetic Counseling ; Preimplantation Diagnosis ; Exome Sequencing ; East Asian People

OBJECTIVE: To assess the feasibility of first polar body transfer (PB1T) combined with preimplantation mitochondrial genetic testing for blocking the transmission of a pathogenic mitochondrial DNA 8993T>G mutation. METHODS: A Chinese family affected with Leigh syndrome which had attended the Reproductive Medicine Centre of the First Affiliated Hospital of Anhui Medical University in September 2021 was selected as the study subject. Controlled ovarian hyperstimulation was carried out for the proband after completing the detection of the mitochondrial DNA 8993T>G mutation load among the pedigree members. Mature MII oocytes were inseminated by intracytoplasmic sperm injection (ICSI), cultured in vitro for 5 to 6 days to the blastocyst stage, and trophoblastocytes were obtained by microbiopsy. Mitochondrial DNA testing (PGT-MT) and chromosomal aneuploidy (PGT-A) analyses were carried out after whole-genome amplification, and the embryos with zero mutation load were selected for transfer. Amniotic fluid and umbilical cord blood samples were collected during middle pregnancy and after birth respectively for mitochondrial DNA testing to verify the reliability of embryo screening. As an attempt, PB1 with good morphology of MII oocytes was selected for transfer into the enucleated oocytoplasm from healthy donors, followed by ICSI fertilization, blastocyst culture and PGT of embryos using the same procedure. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University (No. 2021zhyx-B12). RESULTS: An antagonist protocol was used for ovarian stimulation, and a total of 19 oocytes were obtained, of which 14 MII were fertilized by ICSI, and 2 had developed into blastocysts. PGT-MT was carried out on biopsied trophoblastocytes, in which the mitochondrial DNA 8993T>G mutation load was not detected in one embryo, the other was 100% mutated, and the mutation loads of the remaining unfertilized eggs and developmentally arrested embryos ranged from 0% ~ 100%, presenting a clear biased distribution. With fully informed consent, one PGT-MT zero mutation load blastocyst was transferred and clinical pregnancy was achieved. Mitochondrial DNA and chromosomal testing of amniotic fluid cells during middle pregnancy had revealed no abnormalities. The proband had delivered a healthy boy through Caesarean section at 39⁺⁵ weeks of gestation, and no mutation was detected in the cord blood sample. Five well-formed PBs from 14 eggs were selected for PB1 transfer, followed by ICSI and culture, and two of the reconstituted embryos had formed blastocysts, with none of the above mutations detected in the biopsied samples. CONCLUSION The PGT-MT technology can help families affected with mitochondrial diseases to have healthy offspring. PB1 transfer in combination with ICSI and PGT-MT holds the promise of turning waste into treasure and providing an alternative means of fertility for such families.
Humans ; Preimplantation Diagnosis/methods* ; Female ; DNA, Mitochondrial/genetics* ; Genetic Testing/methods* ; Pregnancy ; Mitochondrial Diseases/genetics* ; Polar Bodies ; Adult ; Feasibility Studies ; Sperm Injections, Intracytoplasmic/methods* ; Embryo Transfer/methods* ; Mutation ; Male ; Blastocyst/metabolism* ; Pedigree

OBJECTIVE: To analyze the chromosome status of pre-implantation embryos from women of different ages, and assess the impact of age on it. METHODS: A retrospective analysis was carried out on the results of PGT-A and PGT-M+PGT-A cycles by whole-genome amplification followed by next generation sequencing at the Second People's Hospital of Nanning between July 2021 and November 2023. The embryos were divided into five groups based on the women's age: ≤ 30 years old group, 31 ~ 34 years old group, 35 ~ 37 years old group, 38 ~ 40 years old group, and ≥ 41 years old group.The chromosomal status of embryos for each group was compared. This study has been approved by the Ethic Committee of the Hospital (Ethics No. Y2024312A). RESULTS: This study has involved 390 couples and 436 PGT cycles, with a total of 1 651 blastocysts biopsied and analyzed. Among these, 835 embryos (50.6%) were found to have chromosomal abnormalities, including 490 (29.7%) with aneuploidies, 154 (9.3%) with chromosomal segment abnormalities, and 264 (16.0%) with chromosome mosaicisms. After adjusting the dosages of Gn, female BMI, male age, PGT indications, infertility type, LH, AMH and other parameters, maternal age appeared to be an independent factor for chromosomal abnormalities and aneuploidies in blastocysts (OR = 1.132, 95%CI = 1.089-1.177, P < 0.001; OR = 1.250, 95%CI = 1.188-1.315, P < 0.001). With the increase in female age, embryonic chromosome abnormalities have significantly increased in each group, with the rates being 32.3% (126/390), 43.1% (189/439), 45.1% (116/257), 66.3% (250/377), and 81.9% (154/188) (P < 0.001). Chromosomal aneuploidies have also significantly increased, with the rates being 8.2% (32/390), 16.6% (73/439), 24.5% (63/257), 49.6% (187/377), and 71.8% (135/188) (P < 0.001). The proportion of embryos with ≥ 2 chromosome abnormalities also significantly increased in abnormal embryos, with the rates being 28.6% (36/126), 30.2% (57/189), 39.7% (46/116), 48.4% (121/250), and 64.9% (100/154) (P < 0.001). Of note, the female age did not affect the prevalence of chromosomal segment abnormalities and mosaicisms (all P > 0.05). CONCLUSION Above findings suggested that along with the increase in female age, there is an increase in the rate and complexity of chromosomal abnormalities, which may contribute to infertility in women with elder age.
Humans ; Female ; Maternal Age ; Adult ; Retrospective Studies ; Chromosome Aberrations ; Preimplantation Diagnosis/methods* ; Pregnancy ; Blastocyst/metabolism* ; Aneuploidy ; Fertilization in Vitro ; Male

OBJECTIVE: To provide preimplantation genetic testing (PGT) for a patient with Incontinentia pigmenti (IP) due to IKBKG gene variant but without family samples through construction of single nucleotide polymorphism (SNP)-based haplotype by Long-read sequencing (LRS) technology. METHODS: A female IP patient with a heterozygous IKBKG c.1167dup variant but without family genetic data who sought genetic counseling at Women and Children' Hospital of Ningbo University in November 2021 was selected as the study subject. The IKBKG gene has a highly homologous pseudogene IKBKGP1. Genomic DNA was extracted from peripheral blood samples from the couple, and LRS was used to obtain informative SNP loci flanking the variant locus, enabling the construction of SNP haplotype with a long segment spanning from the non-homologous region of IKBKG to the variant site. Trophoblast cells were biopsied from blastocysts fertilized through intracytoplasmic sperm injection, and next-generation sequencing (NGS) was used to determine the SNP information of the embryos. Linkage analysis with the parental SNP haplotypes was conducted to detect the carrier status of the embryos and exclude chromosomal aneuploidies. Sanger sequencing was carried out to validate the result. A euploid embryo without the pathogenic variant was selected for transfer. Prenatal diagnosis was carried out by amniocentesis at mid-trimester to verify the result of PGT tests, and follow-up was conducted after the baby was born. This study has been approved by the Ethics Committee of Women and Children's Hospital of Ningbo University (Ethics No. EC2023-094). RESULTS: A total of seven blastocysts were tested, and PGT results indicated that two embryos were euploid and did not carry the pathogenic variant. One euploid embryo was transferred, which resulted in a singleton pregnancy. Amniocentesis at 24 weeks of gestation confirmed that the status of fetal IKBKG gene, and its chromosomal status was consistent with the PGT results. A healthy male infant was born at 38+6 weeks of gestation. CONCLUSION For IP patients with de novo mutation or without family genetic samples, PGT with LRS can directly construct the SNP-based haplotype while avoiding interference from pseudogenes, providing an effective strategy for PGT.
Female ; Humans ; Male ; Pregnancy ; Genetic Testing/methods* ; Haplotypes/genetics* ; High-Throughput Nucleotide Sequencing/methods* ; I-kappa B Kinase/genetics* ; Incontinentia Pigmenti/diagnosis* ; Polymorphism, Single Nucleotide/genetics* ; Preimplantation Diagnosis/methods* ; Infant, Newborn

OBJECTIVE: To block family transmission of a small fragment copy number variation (CNV) with combined 1 Mb resolution preimplantation genetic testing for aneuploidy (PGT-A) and target region preimplantation genetic testing for monogenic disease (PGT-M) strategies. METHODS: A couple who attended the Reproductive and Genetic Medicine Center of Dalian Women and Children's Medical Center (Group) in 2024 were selected as the study subject. Upon the woman's two pregnancies, ultrasound examination revealed fetal abnormalities, and CNV-seq based on low-depth whole genome sequencing revealed that both fetuses had carried a maternal 17p12 microduplication of approximately 1.43 Mb. Microduplication in this region has been associated with Charcot-Marie-Tooth disease type 1A. In view of the fact that the resolution of conventional PGT-A detection cannot meet the requirement of small fragment CNV analysis, and conventional PGT-M assay cannot directly determine the CNV, two detection schemes were adopted. On the one hand, PGT-A testing with 1 Mb resolution was performed on the embryo to directly determine whether it carries the above microduplication. At the same time, the couple and their fetus were subjected to chromosomal typing scheme for the 17p12 region to indirectly identify embryos carrying the risk chromosome for microduplication. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No: FEJT-KY-2025-51). RESULTS: Three embryos were tested after the first PGT cycle, of which 1 was not carrying the pathogenic variant and was euploid, whilst the other 2 embryos were carrying the 17p12 microduplication, and 1 of them was aneuploid. After genetic counseling, the euploid embryo without the 17p12 microduplication was selected for transfer, and prenatal diagnosis based on amniotic fluid sample showed that the fetal chromosomal karyotype was normal and did not carry the 17p12 microduplication. CONCLUSION The combined application of high-resolution PGT-A and PGT-M typing detection of the target region can effectively block family transmission of the CNVs of small fragments.
Humans ; Female ; DNA Copy Number Variations/genetics* ; Preimplantation Diagnosis/methods* ; Pregnancy ; Pedigree ; Genetic Testing/methods* ; Male ; Adult ; Aneuploidy ; Chromosomes, Human, Pair 17/genetics* ; China ; East Asian People

OBJECTIVE: To block the transmission of Cranio-facial-nasal syndrome (CFNS) caused by a large deletion of the EFNB1 gene through preimplantation genetic testing for monogenic disorders (PGT-M). METHODS: A patient with craniofacial deformities and his parents who had visited Shiyan People's Hospital in June 2020 were selected as the study subjects. The child underwent whole exome sequencing (WES) and qPCR validation. After genetic counseling, PGT-M was chosen for the reproductive blockage. This study was approved by the Ethics Committee of the Hospital (Ethics No.: sysrmyy-087). RESULTS: The child was diagnosed with CFNS due to a heterozygous deletion of exons 1-5 of the EFNB1 gene through WES and qPCR, which showed a X-linked dominant inheritance. The mother underwent ovarian stimulation with a modified PPOS protocol, which has yielded 11 oocytes. After ICSI fertilization, 4 blastocysts were formed, and MALBAC whole genome amplification was performed on the trophoblast biopsy cells, and SNP haplotypes of the family members and embryos were analyzed to indirectly determine the presence of maternal pathogenic haplotypes. Chromosomal copy number variation analysis was conducted through next-generation sequencing to screen for euploid embryos, resulting in the identification of two euploid embryos that did not carry the mutation of the EFNB1 gene. The first transfer was unsuccessful, but after adjusting the transfer timing through endometrial receptivity assessment (ERA), clinical pregnancy was achieved. Prenatal diagnosis at 19 weeks excluded the EFNB1 gene exons 1-5 deletion in the fetus. A healthy girl was delivered by Cesarean section at 38⁺⁶ weeks, and Q-PCR confirmed she has no aforementioned EFNB1 gene deletion. CONCLUSION This study has successfully blocked the transmission of CFNS caused by a large deletion of the EFNB1 gene (exons 1-5) using a PGT-M strategy, which may provide reference for the intervention of similar genomic variations that cannot be directly detected.
Humans ; Female ; Male ; Craniofacial Abnormalities/diagnosis* ; Ephrin-B1/genetics* ; Polymorphism, Single Nucleotide/genetics* ; Preimplantation Diagnosis/methods* ; Pedigree ; Asian People/genetics* ; Craniosynostoses/genetics* ; Pregnancy ; Gene Deletion ; Sequence Deletion ; Genetic Testing/methods* ; Adult ; East Asian People

OBJECTIVE: To investigate the results of preimplantation genetic testing for monogenic diseases (PGT-M) in a Chinese pedigree affected with Primary carnitine deficiency (PCD). METHODS: A pedigree affected with PCD who visited Hainan Women and Children's Medical Center in April 2023 due to "SLC22A5 gene mutation found in offspring genetic testing and preparing for a second child" was selected as the study subject. Pathogenicity of the proband's variant sites was determined by referring to the Standards and Guidelines for the Interpretation of Sequence Variants established by the American College of Medical Genetics and Genomics (ACMG). Sanger sequencing was used to verify the variant sites of SLC22A5 gene in the proband and her parents, and the single nucleotide polymorphism (SNP) haplotype of the family was constructed by SNP microarray (SNP array) method to determine the carrier status of pathogenic genes. After fertilization via assisted reproductive technology, whole genome amplification (WGA) was performed on the biopsied trophoblastic cells. Sanger sequencing, next-generation sequencing (NGS), and SNP array techniques were then used to detect the variants in the SLC22A5 gene and chromosome copy number variation (CNV) in the embryos. Embryos without the variants were selected for transferring. After the successful pregnancy of the proband's mother, amniocentesis was not performed for prenatal diagnosis due to repeated vaginal bleeding. After delivery, neonatal peripheral blood sample was collected to verify the results of PGT-M, and follow-up was conducted. This study was reviewed and approved by the Medical Ethics Committee of Hainan Women and Children's Medical Center (Ethics No. HNWCMC-2022-178). RESULTS: In this study, the c.338G>A and c.760C>T variants in SLC22A5 gene were evaluated as pathogenic variants. Sanger sequencing results of this family showed that the c.338G>A and c.760C>T variants of the proband were inherited from his father and mother, respectively. Haplotypes of c.338G>A and c.760C>T variants of SLC22A5 gene were successfully constructed. PGT-M results showed that 2 of the 8 blastulas biopsied failed WGA, and the CNV detection results of the remaining 6 blastocysts were all euploid: 2 had no mutations in the SLC22A5 gene, 3 were single heterozygous carriers of paternal or maternal origin, and 1 was compound heterozygous carriers of paternal and maternal origin. Combined with the embryo morphology score, an intrauterine singleton pregnancy was achieved after the successful transfer of an optimal embryo with no CNV abnormalities and no paternal or maternal SLC22A5 gene mutations, resulting in the birth of a healthy female baby at 38⁺³ weeks of gestation. The results of peripheral blood chromosomal karyotyping analysis, CNV detection and SLC22A5 gene c.338G>A and c.760C>T site variant detection of the infant were consistent with those of PGT-M, and no abnormality was found. CONCLUSION PGT-M had helped the couple carrying SLC22A5 gene variant to have a healthy offspring and effectively blocked the transmission of PCD in this family.
Adult ; Female ; Humans ; Male ; Pregnancy ; Cardiomyopathies ; China ; East Asian People/genetics* ; Genetic Testing/methods* ; High-Throughput Nucleotide Sequencing ; Hyperammonemia/genetics* ; Mutation ; Pedigree ; Polymorphism, Single Nucleotide ; Preimplantation Diagnosis/methods* ; Solute Carrier Family 22 Member 5/genetics* ; Carnitine/deficiency* ; Muscular Diseases

OBJECTIVE: To carry out preimplantation genetic testing for monogenic/single gene disorders (PGT-M) for a Chinese family affected with Molybdenum co-factor deficiency due to pathogenic variant of MOCS2 gene. METHODS: A family with molybdenum co-factor deficiency who attended to the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region in April 2020 was selected as the research subject. Trophoblast cells were biopsied from blastocysts fertilized by intracytoplasmic sperm injection. Embryos carrying the MOCS2 gene variant and chromosome copy number variation (CNV) of more than 4 Mb were detected by single-cell whole genome amplification, high-throughput sequencing and single nucleotide polymorphism typing. Embryos without or carrying the heterozygous variant and without abnormal chromosome CNV were transplanted. During mid-pregnancy, amniotic fluid sample was collected for prenatal diagnosis to verify the results of PGT-M. RESULTS: Eleven oocytes were obtained, among which three blastocysts were formed through culturing. Results of genetic testing suggested that one embryo was heterozygous for the maternally derived MOCS2 gene variant and without chromosomal CNV. Following embryo transfer, intrauterine singleton pregnancy was attained. Prenatal diagnosis by amniocentesis at 18 weeks of gestation revealed that the MOCS2 gene variant and chromosomal analysis results were both consistent with that of PGT-M, and a healthy male infant was born at 37⁺⁵ weeks of gestation. CONCLUSION PGT-M has helped the couple carrying the MOCS2 gene variant to have a healthy offspring, and may become an important method for couples carrying other pathogenic genetic variants.
Female ; Humans ; Pregnancy ; Aneuploidy ; China ; DNA Copy Number Variations ; Genetic Testing/methods* ; Preimplantation Diagnosis/methods* ; Metal Metabolism, Inborn Errors/genetics*