• Journal of Genetic Medicine
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• 제19권2호
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• pp.76-84
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• 2022

Purpose: Whole-exome sequencing (WES) has been a useful tool for novel gene discovery of various disease categories, further increasing the diagnostic yield. This study aimed to investigate the clinical utility of WES prospectively in undiagnosed genetic diseases. Materials and Methods: WES tests were performed on 110 patients (age range, 0-28 years) with suspected rare genetic diseases. WES tests were performed at a single reference laboratory and the variants reported were reviewed by clinical geneticists, pediatricians, neurologists, and laboratory physicians. Results: The patients' symptoms varied with abnormalities in the head or neck, including facial dysmorphism, being the most common, identified in 85.4% of patients, followed by abnormalities in the nervous system (83.6%). The average number of systems manifesting phenotypic abnormalities per patient was 3.9±1.7. The age at presentation was 2.1±2.7 years old (range, 0-15 years), and the age at WES testing was 6.7±5.3 years (range, 0-28 years). In total, WES test reported 100 pathogenic/likely pathogenic variants or variants of uncertain significance for 79 out of 110 probands (71.8%). Of the 79 patients with positive or inconclusive calls, 55 (50.0%) patients were determined to have good genotype-phenotype correlations after careful review. Further clinical reassessment and family member testing determined 45 (40.9%) patients to have been identified with a molecular diagnosis. Conclusion: This study showed a 40.9% diagnostic yield for WES test for a heterogeneous patient cohort with suspected rare genetic diseases. WES could be the feasible genetic test modality to overcome the diversity and complexity of rare disease diagnostics.

• Korean Journal of Radiology
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• 제23권1호
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• pp.101-111
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• 2022

Objective: Familial intracranial aneurysms (FIAs) are found in approximately 6%-20% of patients with intracranial aneurysms (IAs), suggesting that genetic predisposition likely plays a role in its pathogenesis. The aim of this study was to identify possible IA-associated variants using whole exome sequencing (WES) in selected Korean families with FIA. Materials and Methods: Among the 26 families in our institutional database with two or more IA-affected first-degree relatives, three families that were genetically enriched (multiple, early onset, or common site involvement within the families) for IA were selected for WES. Filtering strategies, including a family-based approach and knowledge-based prioritization, were applied to derive possible IA-associated variants from the families. A chromosomal microarray was performed to detect relatively large chromosomal abnormalities. Results: Thirteen individuals from the three families were sequenced, of whom seven had IAs. We noted three rare, potentially deleterious variants (PLOD3 c.1315G>A, NTM c.968C>T, and CHST14 c.58C>T), which are the most promising candidates among the 11 potential IA-associated variants considering gene-phenotype relationships, gene function, co-segregation, and variant pathogenicity. Microarray analysis did not reveal any significant copy number variants in the families. Conclusion: Using WES, we found that rare, potentially deleterious variants in PLOD3, NTM, and CHST14 genes are likely responsible for the subsets of FIAs in a cohort of Korean families.

• 대한유전성대사질환학회지
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• 제17권3호
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• pp.96-102
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• 2017

당원병 IX형은 phosphorylase kinase 효소 결핍으로 분해되지 않은 당원이 간 또는 근육에 축적되는 유전성대사이상질환이다. 당원병 IXa형은 당원병 IX형 중 가장 흔한 형태로 PHKA2 유전자 변이로 발생한다. 당원병 IXa형의 임상증상은 간 비대, 간 효소 수치 상승, 성장 지연, 저혈당 등이 있다. 그러나, 이러한 임상 증상은 다른 타입의 당원병의 증상과 비슷하거나 겹쳐서 임상적으로는 구분하기가 어렵다. 저자들은 표적 엑솜 시퀀싱으로 진단된 가족성 당원병 IXa형 증례를 보고하고자 한다. 4세 남아가 간 비대와 간 효소 수치 상승을 주소로 내원하였다. 간 조직검사결과 간세포에 당원이 축적되어 있어 당원병을 의심하였으나 G6PC 유전자 검사는 음성이었다. 이에 당원병 타입을 감별진단 하기 위해 표적 엑솜시퀀싱을 시행하였으며, PHKA2 유전자에서 질환과의 연관성이 이미 보고된 바 있는 c.3632C>T (p.Thr121Met) 변이가 반접합체(hemizygote)로 발견되어 당원병 IXa로 진단하였다. 가족 유전자 검사를 통해 어머니가 이형접합체 보인자임을 확인하였으며, 남동생이 같은 변이를 가진 반접합체임을 확인하였다. 28개월 된 환자의 남동생 역시 신체 검진 상 간 비대가 있었으며, 혈액검사상 간 효소 수치가 상승되어 있어 같은 질환으로 확진하였다. 이환된 형제 모두 생 옥수수 전분 섭취와 복합 탄수화물을 섭취하도록 식이 조절을 하였으며 2년 추적관찰 동안 정상 성장 발달을 보이고 있다. 당원병과 같이 임상적으로 구분이 어려우며 유전학적으로 다양한 유전자 변이를 보이는 당원병과 같은 질환의 분자 유전학적 감별진단에 표적 엑솜 시퀀싱이 유용한 진단법이 될 수 있다. 신속하고 정확한 분자 유전학적 감별진단을 통해 환자와 보호자에게 질병의 적절한 치료법, 질병의 예후에 관한 정확한 정보를 제공할 수 있을 뿐 아니라, 적절한 유전상담을 제공할 수 있다.

• Integrative Medicine Research
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• 제6권2호
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• pp.165-178
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• 2017

Background: Traditional Korean Sasang constitutional (SC) medicine categorizes individuals into four constitutional types [Tae-eum (TE), So-eum (SE), Tae-yang (TY), or So-yang (SY)] based on biological and physiological characteristics. As these characteristics are closely related to the bioenergetics of the human body, we assessed the correlation between SC type and energy metabolism features. Methods: Forty healthy, young ($22.3{\pm}1.4$ years) males volunteered to participate in this study. Participants answered an SC questionnaire, and their face shape, voice tone, and body shape were assessed using an SC analysis tool. Thirty-one participants (10 TE, 10 SE, 3 TY, and 8 SY) were selected for further analysis. Collected blood samples were subjected to blood composition analysis, mitochondrial function analysis, and whole-exome sequencing. Results: The SY type showed significantly lower total cholesterol and high-density lipoprotein cholesterol levels than the SE type. Cellular and mitochondrial Adenosine triphosphate (ATP) levels were similar across types. All types showed similar basal mitochondrial oxygen consumption rates, whereas the TE type showed a significantly lower ATP-linked oxygen consumption rate than the other types. Whole-exome sequencing identified several genes variants that were exclusively detected in particular SC types, including 19 for SE, seven for SY, 11 for TE, and six for TY. Conclusion: SC type-specific differences in mitochondrial function and gene mutations were detected in a small group of healthy, young Korean males. These results are expected to greatly improve the accurate screening and utilization of SC medicine.

• Korean Journal of Radiology
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• 제23권5호
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• pp.568-569
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• 2022

• Journal of mucopolysaccharidosis and rare diseases
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• 제3권1호
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• pp.28-32
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• 2017

Lipoid congenital adrenal hyperplasia (LCAH) is the severe form of congenital adrenal hyperplasia and is characterized by adrenal insufficiency with hyperpigmentation and female external genitalia irrespective of genetic sex. The steroidogenic acute regulatory protein (StAR) is required for the transport of cholesterol into the mitochondria for steroidogenesis, and defects in the StAR gene account for the majority of LCAH cases. In this report, we present a two-day-old hyperpigmented infant with phenotypical female genitalia. With consideration of the clinical and laboratory findings, the infant was suspected of having adrenal insufficiency due to LCAH and treated with glucocorticoid, mineralocorticoid, and sodium chloride. Karyotyping revealed 46, XY. Upon pelvis ultrasonography, adrenal hyperplasia with abdominal masses (thought to be the testicles) was reported. Molecular analysis with targeted exome sequencing revealed the homozygote mutation of c.772C>T ($p.Q258^*$) in exon 7 of the StAR gene. The early detection and treatment of adrenal insufficiency in infants with hyperpigmentation can prevent clinically apparent adrenal crises. During follow-up, the patient had a good clinical condition and maintained normal electrolyte and adrenocorticotropic hormone levels with medication.

• Genomics & Informatics
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• 제11권1호
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• pp.46-51
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• 2013

Normal-karyotype acute myeloid leukemia (NK-AML) is a highly malignant and cytogenetically heterogeneous hematologic cancer. We searched for somatic mutations from 10 pairs of tumor and normal cells by using a highly efficient and reliable analysis workflow for whole-exome sequencing data and performed association tests between the NK-AML and somatic mutations. We identified 21 nonsynonymous single nucleotide variants (SNVs) located in a coding region of 18 genes. Among them, the SNVs of three leukemia-related genes (MUC4, CNTNAP2, and GNAS) reported in previous studies were replicated in this study. We conducted stepwise genetic risk score (GRS) models composed of the NK-AML susceptible variants and evaluated the prediction accuracy of each GRS model by computing the area under the receiver operating characteristic curve (AUC). The GRS model that was composed of five SNVs (rs75156964, rs56213454, rs6604516, rs10888338, and rs2443878) showed 100% prediction accuracy, and the combined effect of the three reported genes was validated in the current study (AUC, 0.98; 95% confidence interval, 0.92 to 1.00). Further study with large sample sizes is warranted to validate the combined effect of these somatic point mutations, and the discovery of novel markers may provide an opportunity to develop novel diagnostic and therapeutic targets for NK-AML.

• Genes and Genomics
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• 제40권12호
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• pp.1339-1349
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• 2018

Cerebral palsy (CP) is a non-progressive neurological disease, of which susceptibility is linked to genetic and environmental risk factors. More and more studies have shown that CP might be caused by multiple genetic factors, similar to other neurodevelopmental disorders. Due to the high genetic heterogeneity of CP, we focused on investigating related molecular pathways. Ten children with CP were collected for whole-exome sequencing by next-generation sequencing (NGS) technology. Customized processes were used to identify potential pathogenic pathways and variants. Three pathways (axon guidance, transmission across chemical synapses, protein-protein interactions at synapses) with twenty-three genes were identified to be highly correlated with CP. This study showed that the three pathways associated with CP might be the molecular mechanism of pathogenesis. These findings could provide useful clues for developing pathway-based pharmacotherapies. Further studies are required to confirm potential roles for these pathways in the pathogenesis of CP.

• Journal of Genetic Medicine
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• 제17권2호
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• pp.89-91
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• 2020

Charcot-Marie-Tooth (CMT) disease can be divided mainly into demyelination and axonopathy based on the results of the electrophysiological study. Mitofusin 2, encoded by MFN2 gene, has a crucial role in the fusion of mitochondria, which is known to associate with CMT type 2A as one of the axonal forms. We describe a 44-year-old man with progressive weakness on bilateral legs after noticing foot drop in his early teen. When we examined him at 45 years of age, he presented atrophy on entire legs and with distal muscle weakness on limbs. The nerve conduction study revealed severely decreased amplitude on motor nerve ranging from 0.2 to 4.5 mV, while conduction velocity remained more than 30.4 m/s. The whole-exome sequencing revealed a novel variant c.2228G>T in MFN2 by efficient genetic analysis tool, MutationDistiller. This report will not only expand the mutation spectrum of CMT2A but also introduce a time-saving genetic analysis tool.

• Journal of Interdisciplinary Genomics
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• 제4권1호
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• pp.7-10
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• 2022

Purpose:Maturity onset diabetes of the young (MODY) is the most common hereditary form of diabetes mellitus (DM), with similar clinical manifestations to type 1 or type 2 DM, leading to diagnostic ambiguity. Despite increased genetic research on monogenic DM, studies with Asian populations are limited. Therefore, we investigated mutation in possible monogenic DM and MODY in Korean children and aldolescents. Methods: Targeted panel exome sequencing including 32 targets genes was performed for 41 patients with suspected monogenic DM at Kyungpook National University Children's Hospital. Results: Variants were detected in 19 patients, including those in known MODY-associated genes (HNF4A, GCK, HNF1A, CEL, PAX4, INS, and BLK) and monogenic DM-associated genes (WFS1, FRX6, and GLIS3). Conclusion: MODY variants were detected more than expected. Targeted exon sequencing is helpful in diagnosing MODY or possible monogenic DM patients.