• Clinical and Experimental Pediatrics
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• v.58 no.8
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• pp.313-316
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• 2015

Interstitial deletions involving the chromosome band 15q22q24 are very rare and only nine cases have been previously reported. Here, we report on a 12-day-old patient with a de novo 15q22q23 interstitial deletion. He was born by elective cesarean section with a birth weight of 3,120 g at 41.3-week gestation. He presented with hypotonia, sensory and neural hearing loss, dysmorphism with frontal bossing, flat nasal bridge, microretrognathia with normal palate and uvula, thin upper lip in an inverted V-shape, a midline sacral dimple, severe calcanovalgus at admission, and severe global developmental delay at 18 months of age. Fluorescence in situ hybridization findings confirmed that the deleted regions contained at least 15q22. The chromosome analysis revealed a karyotype of 46,XY,del(15) (q22q23). Parental chromosome analysis was performed and results were normal. After reviewing the limited literature on interstitial 15q deletions, we believe that the presented case is the first description of mapping of an interstitial deletion involving the chromosome 15q22q23 segment in Korea. This report adds to the knowledge of the clinical phenotype associated with the 15q22q23 deletion.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.19-24
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• 2016

Constitutional interstitial deletions of the long arm of chromosome 5 (5q) are quite rare, and the corresponding phenotype is not yet clearly delineated. Severe mental retardation has been described in most patients who present 5q deletions. Specifically, the interstitial deletion of chromosome 5q33.3q35.1, an extremely rare chromosomal aberration, is characterized by mental retardation, developmental delay, and facial dysmorphism. Although the severity of mental retardation varies across cases, it is the most common feature described in patients who present the 5q33.3q35.1 deletion. Here, we report a case of a de novo deletion of 5q33.3q35.1, 46,XY,del(5)(q33.3q35.1) in an 11-year-old boy with mental retardation; to the best of our knowledge this is the first case in Korea to be reported. He was diagnosed with severe mental retardation, developmental delay, facial dysmorphisms, dental anomalies, and epilepsy. Chromosomal microarray analysis using the comparative genomic hybridization array method revealed a 16-Mb-long deletion of 5q33. 3q35.1(156,409,412-172,584,708)x1. Understanding this deletion may help draw a rough phenotypic map of 5q and correlate the phenotypes with specific chromosomal regions. The 5q33.3q35.1 deletion is a rare condition; however, accurate diagnosis of the associated mental retardation is important to ensure proper genetic counseling and to guide patients as part of long-term management.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.105-110
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• 2004

Objectives: Despite severe oligospermia, males with Y chromosome microdeletion can achieve conception through ICSI (Intracytoplasmic Sperm Injection). However, ICSI may not only result in the transmission of microdeletions but also the expansion of deletion to the offspring. The purpose of this study was to screen vertical transmission, expansion of microdeletions and de novo deletion in male fetuses conceived by ICSI. Materials and Methods: A total of 32 ICSI treated patients with their 33 (a case of twin) male fetuses conceived by ICSI were used to make this study group. Sequence-tagged sites (STSs)-based PCR analyses were performed on genomic DNA isolated from peripheral blood of fathers and from the amniocytes of male fetuses. Ten primer pairs namely, sY134, sY138, MK5, sY152, sY147, sY254, sY255, SPGY1, sY269 and sY158 were used. The samples with deletions were verified at least three times. Results: We detected a frequency of 12.5% (4 of the 32 patients) of microdeletions in ICSI patients. In 4 patients with detected deletions, two patients have proven deletions on single STS marker and their male fetuses have the identical deletion in this region. Another two patients have two and three deletions, but their male fetuses have more than 3 deletions which include deletions to their father's. Meanwhile, seven male fetuses, whose fathers were analyzed to have all 10 STS markers present, have deletions present in at least one or more of the markers. Conclusions: Although the majority of deletions on the Y chromosome are believed to arise de novo, in some cases a deletion has been transmitted from the fertile father to the infertile patient. In other cases the deletion was transmitted through ICSI treatment, it is likely that one sperm cell is injected through the oocyte's cytoplasm and fertilization can be obtained from spermatozoa. Our tests for deletion were determined by PCR and our results show that the ICSI treatment may lead to vertical transmission, expansion and de novo Y chromosome microdeletions in male fetuses. Because the sample group was relatively small, one should be cautious in analyzing these data. However, it is important to counsel infertile couples contemplating ICSI if the male carries Y chromosomal microdeletions.

• Journal of Genetic Medicine
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• v.12 no.1
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• pp.49-56
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• 2015

We herein report an analysis of a female baby with a de novo dup(10p)/del(10q) chromosomal aberration. A prenatal cytogenetic analysis was performed owing to abnormal ultrasound findings including a choroid plexus cyst, prominent cisterna magna, and a slightly medially displaced stomach. The fetal karyotype showed additional material attached to the terminal region of chromosome 10q. Parental karyotypes were both normal. At birth, the baby showed hypotonia, upslanting palpebral fissures, a nodular back mass, respiratory distress, neonatal jaundice and a suspicious polycystic kidney. We ascertained that the karyotype of the baby was 46,XX,der(10)($pter{\rightarrow}q26.3::p11.2{\rightarrow}pter$) by cytogenetic and molecular cytogenetic analyses including high resolution GTG-and RBG-banding, fluorescence in situ hybridization, comparative genomic hybridization, and short tandem repeat marker analyses. While almost all reported cases of 10p duplication originated from one of the parents with a pericentric inversion, our case is extraordinarily rare as the de novo dup(10p)/del(10q) presumably originated from a rearrangement at the premeiotic stage of the parental germ cell or from parental germline mosaicism.

• Journal of Genetic Medicine
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• v.17 no.1
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• pp.51-54
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• 2020

Since the American College of Medical Genetics and Genomics and Association of Molecular Pathology published their guidelines in 2015, most interpretations of genetic tests have followed them. However, all variants have only limited evidence along 28 interpretation standards, especially de novo variants. When de novo variants, which are classified as variants of uncertain significance (VUS) due to lack of evidence, are detected, segregation in the affected family could provide an important key to clarifying the variants. Autosomal dominant polycystic kidney disease is the most common inherited kidney disorder with pathogenic variants in the PKD1 or PKD2 genes. We detected a novel in-frame deletion variant in the PKD1 gene, c.7575_7577del (p.(Cys2526del)), which was interpreted as a VUS. We analyzed this variant in a Korean family to decide for segregation. Here, we report the variant as a likely pathogenic variant based on the evidence of segregation in three affected relatives and two unaffected members.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.293-296
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• 1999

Different Y mutation in Yq11 occurring de novo in sterile males were first described 19 years ago. Since the phenotype of the patients was always associated with azoospermia or severe oligospermia, it was postulated that these mutations interrupt a Y spermatogenesis locus in the euchromatic Y region (Yq11) called azoospermia factor (AZF). Recently, it became possible to map AZF mutations to different subregions in Yq11by molecular deletion mapping. This indicated that azoospermia is possibly caused by more than one Y gene in Yq11 and the Yq11 chromatin structure. The frequency of AZF mutations in idiopathic sterile males $(5{\sim}20%)$ may indicate a need for a general screening programme for its analysis in infertility clinic. We have experienced a case of deletion distal to Yq11 region in azoospermic patient. So we report this case with a brief review of literatures.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.884-887
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• 2018

We report a female proband carrying a de novo 5q34-q35.2 deletion breakpoint, and review the unique skeletal phenotype and possible genotype related to this mutation. The patient presented with a persistent head tilt and limited head rotation. Non-contrast-enhanced three-dimensional computed tomography of the cervical spine revealed several malformations including a bone cleft in the right pars interarticularis, a bone defect in both C5 lamina and the transverse foramen at C2-C3, agenesis of the right articular process of C5, bony fusion of C4-C5, and subluxation of the craniocervical joints. Several deformities of the cervical spine seen in this patient have not been associated with the 5q deletion. A review of 5q-related mutations suggests that abnormalities associated with MSX2 gene might cause cervical spine abnormalities.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.367-374
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• 2014

Genomes contain a large number of unique genes which have not been found in other species. Although the origin of such "orphan" genes remains unclear, they are thought to be involved in species-specific adaptive processes. Here, we analyzed seven orphan genes (MoSPC1 to MoSPC7) prioritized based on in planta expressed sequence tag data in the rice blast fungus, Magnaporthe oryzae. Expression analysis using qRT-PCR confirmed the expression of four genes (MoSPC1, MoSPC2, MoSPC3 and MoSPC7) during plant infection. However, individual deletion mutants of these four genes did not differ from the wild-type strain for all phenotypes examined, including pathogenicity. The length, GC contents, codon adaptation index and expression during mycelial growth of the four genes suggest that these genes formed during the evolutionary history of M. oryzae. Synteny analyses using closely related fungal species corroborated the notion that these genes evolved de novo in the M. oryzae genome. In this report, we discuss our inability to detect phenotypic changes in the four deletion mutants. Based on these results, the four orphan genes may be products of de novo gene birth processes, and their adaptive potential is in the course of being tested for retention or extinction through natural selection.

• Journal of Genetic Medicine
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• v.2 no.2
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• pp.49-51
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• 1998

Wolf-Hirschhorn syndrome (WHS) is caused by a deletion of the short arm on chromosome 4 and is characterized by multiple congenital abnormalities, growth and mental retardation. In this case report, we performed amniocentesis for the chromosome analysis on a 25-year-old pregnant woman at 16 weeks of gestation whom we suspected of Edward's syndrome by the triple test of maternal serum and ultrasonography. The result of analysis revealed a karyotype of the fetus with 46,XY,del(4)(p15) by trypsin Giemsa's banding technique. With the result, we were able to diagnose the fetus as having WHS. As such, after therapeutic termination of the pregnancy, we confirmed WHS through the sampling of tissue by both trypsin Giemsa's banding and fluorescence in situ hybridization (FISH) method. To determine the origin of the WHS, we further tested the karyotypes of the parents. As parental karyotypes were found to be normal, we determined the case of the fetal WHS to be de novo.

• Genomics & Informatics
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• v.14 no.3
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• pp.70-77
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• 2016

Transposable elements are one of major sources to cause genomic instability through various mechanisms including de novo insertion, insertion-mediated genomic deletion, and recombination-associated genomic deletion. Among them is Alu element which is the most abundant element, composing ~10% of the human genome. The element emerged in the primate genome 65 million years ago and has since propagated successfully in the human and non-human primate genomes. Alu element is a non-autonomous retrotransposon and therefore retrotransposed using L1-enzyme machinery. The 'master gene' model has been generally accepted to explain Alu element amplification in primate genomes. According to the model, different subfamilies of Alu elements are created by mutations on the master gene and most Alu elements are amplified from the hyperactive master genes. Alu element is frequently involved in genomic rearrangements in the human genome due to its abundance and sequence identity between them. The genomic rearrangements caused by Alu elements could lead to genetic disorders such as hereditary disease, blood disorder, and neurological disorder. In fact, Alu elements are associated with approximately 0.1% of human genetic disorders. The first part of this review discusses mechanisms of Alu amplification and diversity among different Alu subfamilies. The second part discusses the particular role of Alu elements in generating genomic rearrangements as well as human genetic disorders.