• Journal of Genetic Medicine
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• 제19권1호
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• pp.7-13
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• 2022

Purpose: Preimplantation genetic testing for monogenic disorders (PGT-M) has been successfully used to prevent couples with monogenic disorders from passing them on to their child. Charcot-Marie-Tooth Disease (CMT) is a genetic disorder characterized by progressive extremity muscle degeneration and loss of sensory function. For the first time in Korea, we report our experience of applying single nucleotide polymorphism genotyping and karyomapping for PGT-M of CMT disease. Materials and Methods: Prior to clinical PGT-M, preclinical tests were performed using genotypes of affected families to identify informative single-nucleotide polymorphisms associated with mutant alleles. We performed five cycles of in vitro fertilization PGT-M in four couples with CMT1A, CMT2A, and CMT2S in CHA Fertility Center, Seoul Station. Results: From July 2020 through August 2021, five cycles of PGT-M with karyomapping in four cases with CMT1 and CMT2 were analyzed retrospectively. A total of 17 blastocysts were biopsied and 15 embryos were successfully diagnosed (88.2%). Ten out of 15 embryos were diagnosed as unaffected (66.7%). Five cycles of PGT-M resulted in four transfer cycles, in which four embryos were transferred. Three clinical pregnancies were achieved (75%) and the prenatal diagnosis by amniocentesis for all three women confirmed PGT-M of karyomapping. One woman delivered a healthy baby uneventfully and two pregnancies are currently ongoing. Conclusion: This is the first report in Korea on the application of karyomapping in PGT-M for CMT patients. This study shows that karyomapping is an efficient, reliable and accurate diagnostic method for PGT-M in various types of CMT diseases.

• Journal of Genetic Medicine
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• 제7권2호
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• pp.125-132
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• 2010

목 적: 착상전 유전진단(preimplantation genetic diagnosis, PGD)은 유전질환을 가진 부부들을 대상으로 체외수정을 통해 획득한 배아에서 유전진단을 하는 방법이다. 다양한 유전질환을 가진 부부에게 그 질환에 맞는 PGD의 설계가 진행되어야 하기 때문에 PGD 시행 전유전상담을 시행하는 것은 PGD 설계에 있어서 매우 중요하다. 이에, PGD 시행 시 필요한 유전상담의 내용에 대해 환자 및 가족과 전문가의 구체적인 의견을 수렴하고 분석하고자 하였다. 대상 및 방법: 본 연구는 PGD에 있어서 유전상담의 필요성과 중요성에 대한 의견을 알아보고자, 2010년 2월 3일부터 4월 30일까지 PGD를 실시 또는 실시 예정인 부부들과 PGD 관련 전문가들을 대상으로 이메일과 직접 설문지를 배포하여 설문조사를 실시하였다. 결 과: 환자 60명과 전문가 31명을 포함하여 총 91명이 설문조사에 응답하였으며, 환자들은 염색체 이상 질환 49명(81.7%)과 단일유전자 이상 질환 11명(18.3%) 이었다. 설문에 응답한 환자와 전문가 모두 유전상담이 PGD의 의료서비스 일환으로 반드시 필요하다고 답하였다. 환자의 충분한 이해를 위하여 필요한 유전상담의 시간에 대해 환자와 가족 그리고 전문가 의견을 수렴한 결과, 각각 45명(75.0%)과 23명(74.2%)이 적정한 유전상담시간을 30분 이상이라고 응답하였다. 하지만, 현 의료시스템에서는 짧은 진료시간 내 진료와 유전상담을 동시에 진행함으로써 환자에게 완벽한 정보제공이 이루어지지 않는 것으로 나타났다. 한편, 전문가 그룹에서는 진료시간의 부족과 유전질환의 정보 부족이 유전상담의 어려운 점이라고 답하였으며, 이에 비 의사(non-MD) 전문유전상담사가 필요하다는 의견이 30명(96.7%)으로 높게 나타났다. 환자와 가족들은 PGD 시술 시 예기치 못한 결과의 가능성, 환자가 가진 유전질환의 위험을 예방할 수 있는 선택사항, 환자가 가지고 있는 유전질환의 위험도 평가, 유전자 검사 시 검사의 목적 설명 및 검사기술의 한계점과 오진률의 설명, PGD 시술 전반에 관한 기술적인 정보 등에 대하여 관심을 가지고 있으며 더 자세한 설명을 필요로 하는 것으로 나타났다. 이에 대한 전문가 의견 역시 환자 및 가족이 관심 있고 자세한 설명을 원하는 정보와 대부분 일치하였다. 이에 따라 환자의 요구와 의견으로 나타난 위의 결과들을 향후 PGD를 위한 유전상담의 지침(guide-line) 구축 시 반영하여야 할 것으로 사료된다. 결 론: 본 연구에서 유전진단과 생식의학 기술의 발전과 더불어 PGD의 적용과 효율성 등에 대한인식이 높아짐에 따라, PGD를 시행함에 있어서 구체적이고 체계적인 유전상담이 필요하다는 것을 확인할 수 있었다. 본 연구의 설문조사 결과가 향후 PGD를 위한 유전상담 지침서(guideline)에 반영되어 적절한 PGD의 설계, 실시, 사후관리에 큰 도움이 되기를 기대한다.

• Clinical and Experimental Reproductive Medicine
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• 제40권1호
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• pp.42-46
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• 2013

Hypochondroplasia (HCH) is an autosomal dominant inherited skeletal dysplasia, usually caused by a heterozygous mutation in the fibroblast growth factor receptor 3 gene (FGFR3). A 27-year-old HCH woman with a history of two consecutive abortions of HCH-affected fetuses visited our clinic for preimplantation genetic diagnosis (PGD). We confirmed the mutation in the proband (FGFR3:c.1620C>A, p.N540K), and established a nested allele-specific PCR and sequence analysis for PGD using single lymphocyte cells. We performed this molecular genetic analysis to detect the presence of mutation among 20 blastomeres from 18 different embryos, and selected 9 embryos with the wild-type sequence (FGFR3:c.1620C). A successful pregnancy was achieved through a frozen-thawed cycle and resulted in the full-term birth of a normal neonate. To the best of our knowledge, this is the first report of a successful pregnancy and birth using single-cell allele-specific PCR and sequencing for PGD in an HCH patient.

• Clinical and Experimental Reproductive Medicine
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• 제38권1호
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• pp.31-36
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• 2011

Objective: To determine whether the serum ${\beta}$-human chorionic gonadotropin (hCG) profile following preimplantation genetic diagnosis (PGD) is lower than that of intracytoplasmic sperm injection (ICSI) cycles. Methods: A total of 129 PGD cycles and 1,161 age-matched ICSI cycles, which resulted in pregnancy (serum ${\beta}-hCG{\geq}5$ mIU/mL) on post-ovulation day (POD) 12 were included. We compared the mean serum ${\beta}$-hCG levels on POD 12, 14, 21, and 28, doubling time of serum hCG, and created a cut-off value for predicting a singleton pregnancy in each group. Results: The mean serum ${\beta}$-hCG concentration of the PGD group was significantly lower than that of the control group on POD 12, 14, and 21. The doubling time of serum ${\beta}$-hCG at each time interval showed no significant difference. The cut-off-value of serum ${\beta}$-hCG for predicting a single viable pregnancy was 32.5 mIU/mL on POD 12 and 113.5 mIU/mL on POD 14 for the PGD group, which was lower than that for the control group. Conclusion: Blastomere biopsy may decrease the ${\beta}$-hCG-producing activity of the trophoblasts, especially in early pregnancy. Setting a lower cut-off value of serum ${\beta}$-hCG for predicting pregnancy outcomes in PGD may be needed.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2001년도 제41차 추계학술대회
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• pp.113.2-113.2
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• 2001

• Clinical and Experimental Reproductive Medicine
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• 제24권1호
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• pp.51-56
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• 1997

Recently, through the development of the primer extension preamplification(PEP) method which amplifies the whole genome, simultaneous multiple DNA analysis has become possible. Whole genome from each single cell can be amplified using 15 base oligonucleotide random primer. The greatest advantage of PEP-PCR is the ability to investigate several loci simultaneously and confirm results by analysing multiple aliquots for each locus. This technique led to the development of preimplantation genetic disease diagnosis using blastomere from early embryo, sperm, polar body and oocyte. In this study, we applied PEP-PCR in 20 cases of single amniocyte and 20 cases of single chorionic villus cell for the clinical application of the prenatal and preimplantational genetic diagnosis. We analysed 7 gene loci simultaneously which are 46, 47 exons related to dystrophin gene, two VNTR (variable number tandem repeat) markers using 5'dysIII, 3'CA related to dystrophin gene and DYZ1, DYZ3, DYS14 regions on chromosome Y. In all the tests, 97.5% of PEP-PCR amplifications with single cells were successful. We obtained 38/40 (95%) accuracy in gender determination through chromosome analysis comparison. Therefore, these results have significant implications for a sperm or oocyte analysis and prenatal or preimplantational genetic diagnosis.

• Clinical and Experimental Reproductive Medicine
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• 제30권2호
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• pp.111-118
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• 2003

Objectives: The development of an useful method for obtaining metaphase chromosomes from a biopsied blastomere would allow differentiation between embryos with balanced and normal chromosome complements in the preimplantation genetic diagnosis for chromosomal translocations. This study was performed to evaluate the effects of microtubule depolymerizing agents (MTDAs) on the blastomeres of mouse and human preimplantation embryos, and to establish an effective method for obtaining metaphase chromosomes of biopsied blastomeres in human early embryos. Materials and Methods: Early embryos (2-4 cell stage) from superovulated mice (ICR strain) were collected and treated with single or mixture MTDAs, such as vinblastine, nocodazole and colcemid. After the treatment of MTDAs for 16 hours, the metaphase aquisition (MA) rates were evaluated by the observation of chromosome status with bis-benzimide or DAPI staining. The optimal condition from the above experiment was applied to human embryos, which were developed from abnormal fertilization (3-pronuclei). Fluorescence in-situ hybridization (FISH) with whole chromosome probes was conducted on the human metaphase chromosomes by the MTDAs. Results: In mouse embryos, the effective concentrations of each MTDAs for obtaining metaphase chromosomes were $1.0{\mu}M$ of vinblastine (20.3%), $5.0{\mu}M$ of nocodazole (28.1%) and $1.0{\mu}M$ colcemid (55.6%), respectively. The highest MA rate (91.2%) in the mouse embryos was obtained by a mixture of vinblastine ($1.0{\mu}M$) and nocodazole ($1.0{\mu}M$). In the human embryos, the metaphase chromosomes of blastomeres were obtained in 44 of 113 blastomeres (38.9%) by treatment of the mixture of vinblastine and nocodazole. FISH signals of the metaphase chromosomes were successfully observed in human individual blastomeres. Conclusions: The treatment of a mixture MTDAs for obtaining metaphase chromosomes was an efficient method, and the MA rate was above 90% in the mouse embryos. However, only a relatively small proportions of the blastomeres yielded metaphase chromosomes by the MTDAs in the human embryos. The inconsistent effects of MTDAs may be related to the variation of different species and the poor developmental potency of abnormally fertilized human embryos. We should develop more reliable and efficient methods for obtaining the metaphase chromosomes in the biopsied blastomeres of human preimplantation embryos.

• Clinical and Experimental Reproductive Medicine
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• 제32권4호
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• pp.293-300
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• 2005

연구목적: 단일 유전자 이상에 대한 착상전 유전진단을 성공적으로 시행하기 위해서는 효과적이고 신뢰도가 높은 PCR 방법의 확립이 중요하다. 본 연구에서는 alkaline lysis와 duplex nested PCR 방법을 단일 림프구와 할구의 유전자 분석에 적용하여 그 효용성을 확인하고자 하였다. 재료 및 방법: 단일 유전자의 이상이 확인된 Duchenne muscular dystrophy (DMD), ornithine transcarbamylase (OTC) 결핍증과 epidermolysis bullosa (EB) 가계의 대상자들에서 채취한 단일 림프구와 공여 받은 배아의 할구를 이용하여 각각 PCR, restriction fragment length polymorphism (RFLP)와 direct DNA sequencing 분석을 시행하였다. 이러한 분석에서 유전자 증폭률 (amplification rate)과 두개의 allele 중에서 하나의 allele이 증폭되지 않는 allele drop-out (ADO) 빈도에 대해 살펴보았다. 결 과: 단일 림프구와 할구를 이용한 PCR 방법의 유전자 증폭률은 DMD에서 91.1%와 81.8%, OTC 결핍증에서 96.0%와 78.1%, EB에서 91.3%와 90.0%를 각각 나타냈으며, ADO 빈도는 OTC 결핍증에서 13.3%, EB에서 16.8%로 관찰되었다. 결 론: 본 연구에서 적용한 alkaline lysis와 duplex nested PCR 방법은 단일 유전자에 대한 착상전 유전진단에 성공적으로 적용할 수 있는 방법으로 생각되며, ADO 빈도를 최소화할 수 있는 효율적인 방법의 개발에 대한 지속적인 연구가 필요하다.

• Clinical and Experimental Reproductive Medicine
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• 제39권3호
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• pp.118-124
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• 2012

Objective: To review the outcomes of preimplantation genetic diagnosis (PGD) using zona drilling with acid Tyrode's solution (chemical zona pellucida drilling, chemical ZD) and those of partial zona dissection (PZD). Methods: Clinical outcomes of seventy-one couples undergoing 85 PGD cycles from January 2005 to December 2010 were included. Blastocyst formation and the hatching rate, clinical pregnancy rate, ongoing pregnancy rate, implantation rate, and fetal gender ratio of the PZD and chemical ZD groups were compared. Results: Application of PZD resulted in a significantly higher rate of clinical pregnancy (40.7% vs. 15.4%, p=0.022), ongoing pregnancy (35.6% vs. 11.5%, p=0.023), and implantation (18.1% vs. 5.7%, p=0.007) compared with chemical ZD. Among non-transferred embryos, the rate of blastocyst formation on day 5 (49.1% vs. 39.5%, p=0.016) and hatching on day 6 (47.2% vs. 26.5%, p<0.001) were also significantly higher in the PZD group. Conclusion: The mechanical zona dissection (ZD) method showed better outcomes than chemical ZD in terms of the blastocyst development and pregnancy rate. In this study, the fact that chemical ZD was conducted in different period from mechanical method should be considered in interpreting the result.

• Clinical and Experimental Reproductive Medicine
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• 제26권1호
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• pp.9-20
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• 1999

The genetic defects in human gametes and embryos can cause adverse effects on overall reproductive events. Biopsy of embryos for preimplantation genetic diagnosis (PGD) offers a new possibility of having children free of the genetic disease. In addition, advanced embryo culture method may enhance the effectiveness of embryo biopsy for the practical application of PGD. This experimental study was undertaken to evaluate the effects of coculture on the development in vitro of biopsied mouse embryos as a preclinical model for PGD of human embryos. Embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BLfemale/CBAmale). Using micromanipulation, 1, 2, 3 or 4 blastomeres of 8-cell stage embryos were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acidic Tyrode's solution (ATS). After biopsy of blastomeres, embryos were cultured in vitro for 110 hours in Ham's F-10 supplemented with 0.4% BSA or cocultured on the monolayer of Vero cells in the same medium. The frequence of blastocyst formation were recorded, and the embryos beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. There was no significant difference in the blastocyst formation between the zona intact control group and the zona drilling (ZD) only, or biopsied groups. The hatching rate of all the treatment groups except 4/8 group was significantly higher than that of control group. In all the treatment groups, there was a significant reduction in the mean cell number of embryos beyond blastocyst stage ($50.2{\pm}14.0$ in control group vs. $41.2{\pm}7.9$ in ZD, $39.3{\pm}8.8$ in 7/8, $29.7{\pm}6.4$ in 6/8, $25.1{\pm}5.7$ in 5/8, and $22.1{\pm}4.3$ in 4/8 groups, p<0.05). When the same treatments were followed by coculture with Vero cells, a similar pattern was seen in the blastocyst formation and the hatching rate. However, in all the treatment groups, there was a significant increase in the mean cell number of embryos beyond blastocyst stage with coculture, compared with the parallel groups without coculture. In the cleavage rate of biopsied blastomeres cultured for 110 hours after IVF, there was no significant difference between coculture and non-coculture groups (87.2% vs. 78.7%). However, the mean cell number of embryos developed from the biopsied blastomeres was significantly higher in coculture group ($11.5{\pm}4.7\;vs.\;5.9{\pm}1.9$, p<0.05). In conclusion, biopsy of mouse embryos after ZD with ATS is a safe and highly efficient method for PGD, and coculture with Vero cells showed a positive effect on the development in vitro of biopsied mouse embryos and blastomeres as a preclinical model for PGD of human embryos.