1.Monocentric Derivative Y Chromosome with Duplication of the SRY Gene in an Azoospermic Male.
Eun Young CHOI ; Bom Yi LEE ; Ju Yeon PARK ; Yeon Woo LEE ; Ah Rum OH ; Shin Young LEE ; Shin Young KIM ; You Jung HAN ; Mee Bum LEE ; Hyun Mee RYU ; Ju Tae SEO ; So Yeon PARK
Journal of Genetic Medicine 2010;7(2):160-164
Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y) (pter-->q11.23::p11.2-->pter).ish der(Y)(DYZ3+,DYZ1-,SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient's father or in the very early stages of embryogenesis. The derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.
Azoospermia
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Biopsy
;
Chromatids
;
Embryonic Development
;
Fathers
;
Female
;
Genes, sry
;
Germ Cells
;
Gonads
;
Heterochromatin
;
Humans
;
Infertility
;
Infertility, Male
;
Karyotype
;
Male
;
Meiosis
;
Oligospermia
;
Phenotype
;
Pregnancy
;
Recombination, Genetic
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Reference Values
;
Siblings
;
Spermatogenesis
;
Varicocele
;
Y Chromosome
2.The Recurrent Pregnancy Loss Associated with a Female Carrier of a Structural Chromosome Rearrangement.
Soomin LEE ; Sanghee GO ; Sookyung JO ; Sohyun PARK ; Soojin MOON ; Dongsuk LEE ; Ki Chul KIM ; Doyeong HWANG
Journal of Genetic Medicine 2010;7(2):156-159
Inversion, one of the balanced rearrangements, usually does not lead to phenotypic abnormalities; all genetic information exists in the proper amount, merely in a different order or in an abnormal location. However, offspring of an inversion carrier is at risk of chromosomal imbalance because an inversion loop can be formed during crossing-over of the paternal and the maternal chromosomes in meiosis. We report a 38-year-old woman with inversion and balanced translocation and her fetus with unusual rearrangement causing chromosomal imbalance. We performed conventional cytogenetic analysis, MLPA, and subtelomeric FISH in the cells of the embryo. The results showed that the distal portion of chromosome 13q was added to the terminal portion of chromosome 9p during crossing-over. Therefore, the final karyotype of the fetus was 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat, confirmed using molecular-cytogenetic analyzing tools.
Adult
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Cytogenetic Analysis
;
Embryonic Structures
;
Female
;
Fetus
;
Humans
;
Karyotype
;
Meiosis
;
Pregnancy
3.A Case of Apert Syndrome with a P253R Mutation on FGFR2 Exon VIII.
Young Jin LEE ; Jung Min KO ; Seong Shik PARK ; Chong Kun CHEON
Journal of Genetic Medicine 2010;7(2):151-155
Apert syndrome is a rare congenital anomaly characterized by craniofacial malformations and severe symmetrical syndactyly of fingers and toes. This syndrome is caused by a genetic mutation; the S253 mutation is common, though the P253R mutation is not as frequent. Common symptoms include skeletal malformations, poor joint mobility, eye and ear problems, cleft palate, and orthodontic and other dental problems. We report a case of an infant with the common morphological features of Apert syndrome. Interestingly, she was found to have the P253R mutation in FGFR2 exon VIII, which has been less commonly observed in Korea. A brief review of the literature is included.
Acrocephalosyndactylia
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Cleft Palate
;
Ear
;
Exons
;
Eye
;
Fingers
;
Humans
;
Infant
;
Joints
;
Korea
;
Syndactyly
;
Toes
4.Acrodysostosis Associated with Symptomatic Cervical Spine Stenosis.
Jung Min KO ; Kyu Sung KWACK ; Sang Hyun KIM ; Hyon Ju KIM
Journal of Genetic Medicine 2010;7(2):145-150
Acrodysostosis is an extremely rare disorder characterized by short fingers and toes with peripheral dysostosis, nasal hypoplasia, and mental retardation. We report a 16-year-old Korean boy with acrodysostosis who had characteristic clinical features and cervical spine stenosis manifested by neurologic symptoms. On presentation, he complained of difficulty in raising his arms, and suffered from intermittent pain and weakness in both upper extremities. He had short stature and dysmorphic facial features, including a broad, depressed nasal bridge, small, upturned nose, bilateral epicanthal folds, and mild hypertelorism. Moderate mental retardation and sensorineural hearing loss in both ears were also present. Radiological findings included broad, short metacarpals and phalanges with cone-shaped epiphyses, bilateral Madelung deformities, hypertrophied first metatarsals, and thickening of the calvarium. Magnetic resonance imaging findings included stenosis of the cervical spine, platybasia with compression into the cervicomedullary junction, and downward displacement of the cerebellar tonsils. Here, we report a case of acrodysostosis with symptoms and signs of cervical spinal stenosis first in Korea. If it is diagnosed in the early stages, possible life-threatening complications, including spinal canal stenosis, can be managed properly and permanent neurologic sequelae might be avoided. Therefore, it is important to consider acrodysostosis in the differential diagnosis of peripheral dysostosis.
Adolescent
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Arm
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Congenital Abnormalities
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Constriction, Pathologic
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Diagnosis, Differential
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Displacement (Psychology)
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Dysostoses
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Ear
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Epiphyses
;
Fingers
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Growth Disorders
;
Hearing Loss, Sensorineural
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Humans
;
Hypertelorism
;
Intellectual Disability
;
Korea
;
Magnetic Resonance Imaging
;
Metacarpal Bones
;
Metatarsal Bones
;
Neurologic Manifestations
;
Nose
;
Osteochondrodysplasias
;
Palatine Tonsil
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Platybasia
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Skull
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Spinal Canal
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Spinal Stenosis
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Spine
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Toes
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Upper Extremity
5.Reduced Number of Endothelial Progenitor Colony-Forming Units in Patients with Preeclampsia.
Shin Young KIM ; So Yeon PARK ; Jin Woo KIM ; Mi Bum LEE ; You Jung HAN ; Hyun Kyong AHN ; Jun Seek CHOI ; Jung Yeol HAN ; Moon Young KIM ; Kyu Hong CHOI ; Hyun Mee RYU
Journal of Genetic Medicine 2010;7(2):138-144
PURPOSE: Endothelial progenitor cells (EPCs), which mediates neovascularization of uterine endometrium may be involved in the neovascularization in the utero-placental circulation. Low numbers of endothelial progenitor colony-forming unit (CFU) in culture are predictive biomarker of vascular disease. The aim of the present study was to evaluate whether the number of CFU in preeclampsia differed from that in normal pregnancy. MATERIALS AND METHODS: Women with singleton normal (n=26) or preeclamptic (n=20) pregnancies were studied during the third trimester. The number of EPCs was quantified by CFU methodology. Plasma levels of angiogenic factors, vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and placental growth factor (PlGF) were determined by enzyme-linked immunoassay. RESULTS: CFU numbers were significantly decreased in the preeclamptic patients compared with the controls (median, 3; range 1-12 vs. 31; 3-81 CFU/well, P<0.001). A majority of the cells comprising individual colonies were positive for endothelial characteristics (Ulex europaeus lectin staining and acetylated low-density lipoprotein uptake). Plasma levels of the sFlt-1 were highly elevated (P<0.001) in patient with preeclampsia compared to controls, whereas PlGF were highly reduced (P=0.004), but these factors did not associate with CFU numbers. CONCLUSION: Our results suggest that reduced numbers of CFU obtained from maternal peripheral blood may contribute to the development of preeclampsia.
Angiogenesis Inducing Agents
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Endometrium
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Female
;
Humans
;
Lipoproteins
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Plasma
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Pre-Eclampsia
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Pregnancy
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Pregnancy Trimester, Third
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Stem Cells
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Tyrosine
;
Vascular Diseases
;
Vascular Endothelial Growth Factor A
6.Genetic Diagnosis of Beckwith Wiedemann Syndrome using Methylation Specific PCR-RFLP Method.
Gu Hwan KIM ; Jin Joo LEE ; Seung Hoon CHOI ; Joo Yeon LEE ; Beom Hee LEE ; Han Wook YOO
Journal of Genetic Medicine 2010;7(2):133-137
PURPOSE: Beckwith-Wiedemann syndrome (BWS) is an overgrowth malformation syndrome caused by a methylation abnormality at chromosome 11p15, consisting of two imprinting centers, BWSIC1 (IGF2, H19) and BWSIC2 (LIT1, KvDMR). This study evaluated the applicability of a methylation-specific (MS) PCR RFLP method for the genetic diagnosis of BWS. MATERIALS AND METHODS: A total of 12 patients were recruited based on clinical findings. Karyotyping was performed using peripheral blood leukocytes, and genomic DNA was treated with bisulfate and amplified using methylation-specific primers. RFLP was conducted with restriction enzymes in differentially methylated regions of LIT1, H19, and IGF2. RESULTS: The 12 BWS patients had normal karyotypes. Abnormal methylation patterns in the BWSIC2 (LIT1) region were identified in seven patients (58.3%) using the MS-PCR RFLP method. CONCLUSIONS: The MS-PCR RFLP method is a simple, economical genetic test. It detected genetic abnormalities in 50-60% of BWS patients, suggesting that it can be used as a screening test. A more precise method is required, however, to enhance the detection rate of genetic abnormalities, especially in BWSIC1 region.
Beckwith-Wiedemann Syndrome
;
DNA
;
Genetic Testing
;
Humans
;
Karyotype
;
Karyotyping
;
Leukocytes
;
Mass Screening
;
Methylation
;
Polymerase Chain Reaction
;
Polymorphism, Restriction Fragment Length
7.A Study of Guidelines for Genetic Counseling in Preimplantation Genetic Diagnosis (PGD).
Min Jee KIM ; Hyoung Song LEE ; Inn Soo KANG ; Seon Yong JEONG ; Hyon J KIM
Journal of Genetic Medicine 2010;7(2):125-132
PURPOSE: Preimplantation genetic diagnosis (PGD), also known as embryo screening, is a pre-pregnancy technique used to identify genetic defects in embryos created through in vitro fertilization. PGD is considered a means of prenatal diagnosis of genetic abnormalities. PGD is used when one or both genetic parents has a known genetic abnormality; testing is performed on an embryo to determine if it also carries the genetic abnormality. The main advantage of PGD is the avoidance of selective pregnancy termination as it imparts a high likelihood that the baby will be free of the disease under consideration. The application of PGD to genetic practices, reproductive medicine, and genetic counseling is becoming the key component of fertility practice because of the need to develop a custom PGD design for each couple. MATERIALS AND METHODS: In this study, a survey on the contents of genetic counseling in PGD was carried out via direct contact or e-mail with the patients and specialists who had experienced PGD during the three months from February to April 2010. RESULTS: A total of 91 persons including 60 patients, 49 of whom had a chromosomal disorder and 11 of whom had a single gene disorder, and 31 PGD specialists responded to the survey. Analysis of the survey results revealed that all respondents were well aware of the importance of genetic counseling in all steps of PGD including planning, operation, and follow-up. The patient group responded that the possibility of unexpected results (51.7%), genetic risk assessment and recurrence risk (46.7%), the reproduction options (46.7%), the procedure and limitation of PGD (43.3%) and the information of PGD technology (35.0%) should be included as a genetic counseling information. In detail, 51.7% of patients wanted to be counseled for the possibility of unexpected results and the recurrence risk, while 46.7% wanted to know their reproduction options (46.7%). Approximately 96.7% of specialists replied that a non-M.D. genetic counselor is necessary for effective and systematic genetic counseling in PGD because it is difficult for physicians to offer satisfying information to patients due to lack of counseling time and specific knowledge of the disorders. CONCLUSIONS: The information from the survey provides important insight into the overall present situation of genetic counseling for PGD in Korea. The survey results demonstrated that there is a general awareness that genetic counseling is essential for PGD, suggesting that appropriate genetic counseling may play a important role in the success of PGD. The establishment of genetic counseling guidelines for PGD may contribute to better planning and management strategies for PGD.
Chromosome Disorders
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Counseling
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Surveys and Questionnaires
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Electronic Mail
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Embryonic Structures
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Fertility
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Fertilization in Vitro
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Follow-Up Studies
;
Genetic Counseling
;
Humans
;
Imidazoles
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Korea
;
Mass Screening
;
Nitro Compounds
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Parents
;
Pregnancy
;
Preimplantation Diagnosis
;
Prenatal Diagnosis
;
Prostaglandins D
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Recurrence
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Reproduction
;
Reproductive Medicine
;
Risk Assessment
;
Specialization
8.Exome Sequencing in Mendelian Disorders.
Journal of Genetic Medicine 2010;7(2):119-124
More than 7,000 rare Mendelian diseases have been reported, but less than half of all rare monogenic disorders has been discovered. In addition, the majority of mutations that are known to cause Mendelian disorders are located in protein-coding regions. Therefore, exome sequencing is an efficient strategy to selectively sequence the coding regions of the human genome to identify novel genes associated with rare genetic disorders. The "exome" represents all of the exons in the human genome, constituting about 1.5% of the human genome. Exome sequencing is carried out by targeted capture and intense parallel sequencing. After the first report of successful exome sequencing for the identification of causal genes and mutations in Freeman Sheldon syndrome, exome sequencing has become a standard approach to identify genes in rare Mendelian disorders. Exome sequencing is also used to search the causal genes and variants in complex diseases. The successful use of exome sequencing in Mendelian disorders and complex diseases will facilitate the development of personalized genomic medicine.
Clinical Coding
;
Exome
;
Exons
;
Genome, Human
;
Humans
9.Clinical Applications of Chromosomal Microarray Analysis.
Journal of Genetic Medicine 2010;7(2):111-118
Chromosomal microarray analysis (CMA) enables the genome-wide detection of submicroscopic chromosomal imbalances with greater precision and accuracy. In most other countries, CMA is now a commonly used clinical diagnostic test, replacing conventional cytogenetics or targeted detection such as FISH or PCR-based methods. Recently, some consensus statements have proposed utilization of CMA as a first-line test in patients with multiple congenital anomalies not specific to a well-delineated genetic syndrome, developmental delay/intellectual disability, or autism spectrum disorders. CMA can be used as an adjunct to conventional cytogenetics to identify chromosomal abnormalities observed in G-banding analysis in constitutional or acquired cases, leading to a more accurate and comprehensive assessment of chromosomal aberrations. Although CMA has distinct advantages, there are several limitations, including its inability to detect balanced chromosomal rearrangements and low-level mosaicism, its interpretation of copy number variants of uncertain clinical significance, and significantly higher costs. For these reasons, CMA is not currently a replacement for conventional cytogenetics in prenatal diagnosis. In clinical applications of CMA, knowledge and experience based on genetics and cytogenetics are required for data analysis and interpretation, and appropriate follow-up with genetic counseling is recommended.
Child
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Autism Spectrum Disorder
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Chromosome Aberrations
;
Coat Protein Complex I
;
Consensus
;
Cytogenetics
;
Diagnostic Tests, Routine
;
Genetic Counseling
;
Genomic Structural Variation
;
Humans
;
Microarray Analysis
;
Mosaicism
;
Prenatal Diagnosis
;
Statistics as Topic
10.Prenatally Diagnosed Uncommon Mosaic Autosomal Trisomy.
Bom Yi LEE ; So Yeon PARK ; Moon Hee LEE ; Jin Woo KIM ; Ju Yeon PARK ; Eun Young CHOI ; Yeon Woo LEE ; Ah Rum OH ; Shin Young LEE ; Min Hyung KIM ; Hyun Mee RYU
Journal of Genetic Medicine 2009;6(1):95-99
Prenatal diagnosis of rare autosome mosaicism involvingchromosomes other than chromosome 13, 18, 21 or the sex chromosome is encountered prognostic dilemma during genetic counseling. We report four cases of level III uncommon mosaicism of trisomy 5, 16 and 20,diagnosed prenatally. In case 1 with mosaic trisomy 20, there was a higher mosaic ratio of trisomy 20 in the repeat amniocentesis (62.1%) than in the first (36.6%) with normal fetal ultrasound finding except for a relatively small aorta on a 3-vessel view of the fetal heart. Case 2 showed a low rate of mosaic trisomy 20 (5.25%) in cultured amniocytes but normal karyotype in the repeat amniocentesis, who delivered a normal healthy baby. Case 3 showed a 13.6% of trisomy 16 mosaicism in the 30 cells of cultured amniocytes. Sixty cells from a fetal blood sample at termination showed non-mosaic 46,XX normal karyotype, while skin fibroblasts had 22.5% trisomy 16 in 40 metaphases. The autopsy showed ventricular septal defect (VSD). Case 4 with low grade mosaicism (10.5%) of trisomy 5 resulted in elective termination, though the ultrasoumd showed growsly normal fetus. Although level III mosaicism is regarded as true mosaicism, it is difficult to predict the outcome of the fetus with rare mosaic autosome trisomy. Therefore mosaic autosome trisomy of fetus should be carefully interpreted with more various approaches including repeat sampling and targeted fetal ultrasound.
Amniocentesis
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Aorta
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Autopsy
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Chromosomes, Human, Pair 13
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Chromosomes, Human, Pair 16
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Chromosomes, Human, Pair 20
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Fetal Blood
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Fetal Heart
;
Fetus
;
Fibroblasts
;
Genetic Counseling
;
Heart Septal Defects, Ventricular
;
Karyotype
;
Metaphase
;
Mosaicism
;
Prenatal Diagnosis
;
Sex Chromosomes
;
Skin
;
Trisomy