• YAKHAK HOEJI
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• v.46 no.3
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• pp.179-184
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• 2002

The abuse of dextromethorphan has been prevalent for 15 years in Korea and its fatal cases were reported even though it has proved to be very safe. In this study, to investigate the safety and tolerance assessment of dextromethorphan, the metabolic phenotyping and genotype of dextromethorphan were studied. After a single 30 mg of dextromethorphan oral administration to 74 volunteers, concentration of dextromethorphan and its metabolites, dextrorphan, hydroxymorphinan and methoxymorphinan were measured in urine which collected during 8hrs after the drug administration. CYP2D6 phenotype was determined from the ratio of dextromethorphan to dextrorphan. GC/MS was used to quantify dextromethorphan and its metabolites. For genotyping, mutant alleles of the CYP2D6 gene were identified. 24 subjects (32.4％) were homozygous for CYP2D6＊10B, 29 subjects (39.2％) were heterozygous for this allele, while in 21 subjects (28.4％) no exon 1 mutation could be found. The frequency of CYP2D6＊10B-allele containing the 188C T mutation was 54％ of total subjects studied.

• Journal of Genetic Medicine
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• v.15 no.1
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• pp.17-19
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• 2018

Alkaptonuria (AKU, OMIM: 203500) is a rare autosomal recessive disorder of tyrosine metabolism due to a defect of enzyme activity, homogentisate 1,2-dioxygenase (HGD). The patients with AKU initially presented with dark urine discoloration, and ochronosis and arthritis develop after third decades of life. With advances of Internet resources, web-based health seekers for rare disease are increasing. Here, we report the case of an 18-year-old boy with AKU who visited our center due to dark black urine based on self-diagnosis via web searching of this rare condition. Compound heterozygous mutations in HGD gene, IVS5+3A>C and IVS12+6T>C were identified and both of mutations were detected in his parents. Our case illustrates the utility of publicly available Internet resources for diagnosis of rare disease.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.213.4-213
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• 2003

No Abstract, See Full Text

• Journal of Genetic Medicine
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• v.15 no.2
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• pp.97-101
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• 2018

Tricho-rhino-phalangeal syndrome (TRPS) is a hereditary disorder characterized by craniofacial and skeletal abnormalities. A mutation of the TRPS1 gene leads to TRPS type I or type III. A 20-year-old male patient visited our neurologic department with chronic fatigue. He presented with short stature, sparse hair, pear-shaped nose, and brachydactyly. Radiologic study showed short metacarpals, metatarsals with cone-shaped epiphyses, hypoplastic femur and hip joint. Panel sequencing for OMIM (Online Mendelian Inheritance in Man) listed genes revealed a de novo heterozygous frameshift mutation of c.1801_1802delGA (p.Arg601Lysfs*3) of exon 4 of the TRPS1 gene. The diagnosis of TRPS can be challenging due to the rarity and variable phenotype of the disease, clinicians should be aware of its characteristic clinical features that will lead a higher rate of diagnosis.

• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.57-60
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• 2019

Axonal Charcot-Marie-Tooth disease (CMT2) has most frequently been associated with mutations in the MFN2 gene. MFN2 encodes mitofusin 2, which is a mitochondrial fusion protein that plays an essential role in mitochondrial function. We report CMT2 in a Korean father and his son that manifested with gait difficulties and progressive atrophy of the lower legs. Molecular analysis revealed a novel heterozygous c.2096T>C (p.Leu699Pro) mutation in the exon 18 of MFN2 in both subjects. We suggest that this novel mutation in MFN2 is probably a pathogenic mutation for CMT2.

• Journal of Genetic Medicine
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• v.18 no.1
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• pp.60-63
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• 2021

Gabriel-de Vries syndrome, caused by the mutation of YY1, is a newly defined genetic syndrome characterized by developmental delay, facial dysmorphism, and intrauterine growth retardation. A 7-month-old girl presented developmental delay and subtle facial dysmorphism including facial asymmetry, micrognathia, and low-set ears. Whole exome sequencing identified a de novo heterozygous missense variant in the YY1 (c.1220A>G; p.His407Arg) gene. Here, we examined the clinical and genetic characteristics of an infant with a novel likely pathogenic variant of YY1. This case expands the phenotypic spectrum of Gabriel-de Vries syndrome.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.38-41
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• 2022

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disease caused by mutations in the neurogenic locus notch homolog protein 3 (NOTCH3) gene. The spectrum of clinical manifestations is broad, ranging from asymptomatic to typical ischemic stroke, and mainly depends on the location of the mutations. We describe the case of a 76-year-old female without apparent neurological deficits. However, brain magnetic resonance imaging revealed confluent lesions in the white matter. Direct sequencing of the NOTCH3 gene revealed a novel pathogenic mutation, c.811T>A, which results in a mild phenotype. Therefore, this report will expand the current knowledge in regards to the mutations that can cause CADASIL.

• Journal of Interdisciplinary Genomics
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• v.5 no.1
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• pp.1-4
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• 2023

Kleefstra syndrome is caused by chromosome 9q34.3 deletion or heterozygous mutations in the Euchromatin Histone Methyl Transferase 1 (EHMT1) gene. The prevalence is estimated 1:25,000 to 1:35,000. Intellectual disability, distinctive facial features, hypotonia in childhood can be accompanied. The spectrum of Kleefstra syndrome includes behavioral/psychiatric problems, hearing and visual impairments, seizures, congenital heart defects, genitourinary defects, and obesity. Therefore, it is necessary to understand the pathophysiology and various manifestation of Kleefstra syndrome and discussing with a multidisciplinary team will help diagnose and treat Kleefstra syndrome patients.

• Journal of Genetic Medicine
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• v.20 no.2
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• pp.70-74
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• 2023

CCCTC-binding factor (CTCF) is a transcriptional regulator that binds to a complex DNA motif in various orientations and plays a crucial role in regulating gene expression, chromatin restructuring, and developmental processes. Mutations in the CTCF are associated with neurodevelopmental disorders. Here we report the first Korean case with a de novo heterozygous variant in the CTCF (c.1025G>A; p.Arg342His). She showed global developmental delay, failure to thrive, and dysmorphic face, which are phenotypes consistent with previous reports in the autosomal dominant intellectual developmental disorder 21 (MIM 615502). She also showed clinical features not previously reported, such as antral web and tracheobronchomalacia. Our case follows suit and expands understanding of this rare disorder by reporting common features and, on the other hand, unreported concomitant congenital anomalies.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.77-89
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• 1998

Background: Genetic and environmental factors are known to affect the incidence and severity of asthma. Stimulation of $\beta_2$-Adrenergic Receptor ($\beta_2$AR) results in smooth muscle relaxation, leading to decrease in resistance of airflow. The gene encoding the $\beta_2$AR has recently been seguenced. The $\beta_2$AR genotype at the polymorphic loci of codons 16, 27, 34, and 164 was known to cause changes in the amino acids. The relationships between the structure of the $\beta_2$AR and its functions are being elucidated. Purpose : The gene encoding the $\beta_2$AR was carried out to assess the frequency of polymorphisms in bronchial asthma, to determine wheather these polymorphisms have any relation to the severity, or nocturnal symptoms in bronchial asthma. Methods: The subjects studied were 103 patients with bronchial asthma, which consisted of 30 mild episodic, 32 mild persistent, 17 moderate, and 24 severe asthma patients. The polymorphisms of the $\beta_2$AR gene were detected by mutated allele specific amplification (MASA) method at the codons 16,27,34, and 164. Results: The most frequent polymorphism was arginine 16 to glycine. The other two polymorphisms, valine 34 to methionine and glutamine 27 to glutamic acid occured in 11 and 6 patients respectively. The polymorphism of threonine 164 to isoleucine was not found in our enrolled patients. The homozygous polymorphism of $\beta_2$AR gene was found in only arginine 16 to glycine (12.6%). The heterozygous polymorphisms of $\beta_2$AR gene were in arginine 16 to glycine, valine 34 to methionine, and glutamine 27 to glutamic acid, as 65.1 %,10.7%, and 5.8% respectively in asthma patients. The presence of agrginine 16 to glycine heterozygous or/and homozygous polymorphism was associated in severe asthma (p=0.015), but there was no association between the other three polymorphisms and the severity of asthma. The frequency of the $\beta_2$AR gene polymorphisms was no relation in nocturnal asthma as compared with non-nocturnal asthma. Conclusion: The arginine 16 to glycine polymorphism of the $\beta_2$AR gene is the most frequently found in asthma patients and association with severe asthma. But there was no association between the polymorphism of the $\beta_2$AR gene and nocturnal asthma.