• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1867-1870
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• 2005

The celestial navigation is one of alternatives to GPS system and can be used as a backup of GPS. In the celestial navigation system using more than two star trackers, the vehicle's ground position can be solved based on the star trackers' attitude information if the vehicle's local vertical or horizontal angle is given. In order to determine accurate ground position of flight vehicle, the high accurate local vertical angle measurement is one of the most important factors for navigation performance. In this paper, the Earth geophysical deflection was analyzed in the assumption of using the modern electrolyte tilt sensor as a local vertical sensor for celestial navigation system. According to the tilt sensor principle, the sensor measures the tilt angle from gravity direction which depends on the Earth geoid surface at a given position. In order to determine the local vertical angle from tilt sensor measurement, the relationship between the direction of gravity and the direction of the Earth center should be analyzed. Using a precision orbit determination software which includes the JGM-3 Earth geoid model, the direction of the Earth center and the direction of gravity are extracted and analyzed. Appling vector inner product and cross product to the both extracted vectors, the magnitude and phase of deflection angle between the direction of gravity and the direction of the Earth center are achieved successfully. And the result shows that the angle differences vary as a function of latitude and altitude. The maximum 0.094$^{circ}$angle difference occurs at 45$^{circ}$latitude in case of 1000 Km altitude condition.

• Journal of Genetic Medicine
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• 제19권1호
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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 Genetic Medicine
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• 제18권1호
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• pp.55-59
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• 2021

West syndrome (WS) presenting with infantile spasms, developmental delay, and hypsarrhythmia has genetic etiology in some patients. Movement disorders or visual impairment that share genetic underpinnings with infantile spasms can provide diagnostic clues for specific genetic mutations. Mutations of the GRIN1 gene encoding the glutamate receptor inotropic N-methyl-D-aspartate subunit can result in WS with hyperkinetic movements, cortical visual impairment, autistic features, and bilateral polymicrogyria. An 11-month-old boy with WS showed hyperkinetic movements and visual impairment. Brain magnetic resonance imaging and metabolic investigations revealed no abnormalities. Whole-exome sequencing revealed a novel likely pathogenic variant (c.1561_1563del; p.Asn521del) of GRIN1 (NM_007327.3). The proband was treated with vigabatrin and became seizure-free within one week. Notably, the cortical blindness improved within 3 months and the hyperkinetic movements resolved one year after the proband became seizure-free. To the best of our knowledge, this is the first report of GRIN1 encephalopathy in Koreans.

• Journal of Genetic Medicine
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• 제11권1호
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• pp.36-39
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• 2014

Chromosome 3 (3p) deletion syndrome is a rare genomic disorder caused by a deletion at the terminal end of the short arm of chromosome 3. The primary characteristics of the syndrome are delayed development, dysmorphic features, and several other congenital anomalies. Here, we describe the case of a 2-year-old Korean girl with typical features of 3p deletion syndrome, including dysmorphic facial features, low birth weight, developmental delay, growth and cognitive retardation, and congenital heart disease. This case represents the first report of 3p deletion syndrome in Korea. Although phenotypes can be variable among patients, a clinically recognizable pattern has been described for this genetic defect, and our report helps to identify other cases with 3p deletion syndrome from a clinical and genetic perspective.

• Journal of Genetic Medicine
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• 제17권2호
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• pp.92-96
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• 2020

Hypotonia, Ataxia, and Delayed Development Syndrome (HADDS) is an autosomal-dominant, extremely rare neurodevelopmental disorder caused by the heterozygous EBF3 gene mutation. EBF3 is located on chromosome 10q26.3 and acts as a transcription factor that regulates neurogenesis and differentiation. This syndrome is characterized by dysmorphism, cerebellar hypoplasia, urogenital anomaly, hypotonia, ataxia, intellectual deficit, and speech delay. The current report describes a 3-year-old Korean male carrying a de novo EBF3 mutation, c.589A>G (p.Asn197Asp), which was identified by whole exome sequencing. He manifested facial dysmorphism, hypotonia, strabismus, vermis hypoplasia, and urogenital anomalies, including vesicoureteral reflux, cryptorchidism, and areflexic bladder. This is the first report of a case of HADDS cause by an EBF3 mutation in the Korean population.

• Journal of Genetic Medicine
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• 제10권1호
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• pp.52-56
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• 2013

Mosaic trisomy 14 syndrome is a well-known but unusual chromosomal abnormality with a distinct and recognizable phenotype. Array comparative genomic hybridization (CGH) analysis has recently become a widely used method for detecting DNA copy number changes, in place of traditional karyotype analysis. However, the array CGH shows a limitation for detecting the low-level mosaicism. Here, we report the detailed clinical and cytogenetic findings of patient with low-frequency mosaic trisomy 14, initially considered normal based on usual cut-off levels of array CGH, but confirmed by G-banding karyotyping. Our patient had global developmental delay, short stature, congenital heart disease, craniofacial dysmorphic features, and dark skin patches over her whole body. Estimated mosaicism proportion was 23.3% by G-banding karyotyping and 18.0% by array CGH.

• Journal of Genetic Medicine
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• 제10권2호
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• pp.109-112
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• 2013

Treacher Collins syndrome (TCS) is the most common and well known mandibulofacial dysostosis with characteristic clinical features including downward slanting of palpebral fissures, coloboma of the lower eyelid, hypoplastic zygomatic arches, micrognathia, macrostomia, microtia, and other deformities of the ears. TCS is caused by mutations in at least 3 genes involved in pre-rRNA transcription: TCOF1, POLR1D and POLR1C. We experienced a 1-day-old female infant with characteristic clinical features of TCS. A novel, heterozygotic mutation within the TCOF1 gene (c.3874_3875insG, p.Ala1292Glyfs*30) was identified to cause a premature stop codon.

• Journal of Genetic Medicine
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• 제15권1호
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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.

• Journal of Genetic Medicine
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• 제9권1호
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• pp.35-37
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• 2012

Emanuel syndrome is a rare genomic syndrome which is characterized by multiple congenital anomalies and developmental disability. This syndrome is related to the presence of the supernumerary derivative chromosome originating from both chromosome 11 and 22. In most cases, one of the parents is a balanced carrier of a translocation. Our case results from 3:1 meiotic segregation of the maternal translocation carrier and is a rare case in Korea confirmed by genetic analysis.

• Journal of Genetic Medicine
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• 제15권2호
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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.