• Annals of Clinical Neurophysiology
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• v.22 no.2
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• pp.121-124
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• 2020

The most common form of autosomal recessive hereditary spastic paraplegia (HSP) is caused by mutations in SPG11/KIAA1840 gene, which encodes for spatacsin. The clinical presentation of SPG11 is characterized by cognitive impairment, peripheral neuropathy and a thin corpus callosum in brain magnetic resonance imaging. We identified a novel homozygous nonsense mutation (c.6082C>T [p.Q2028]) in exon 32 of SPG11 in Korean siblings. Our findings suggest that this novel homozygous mutation in SPG11 is associated with HSP and with dysgenesis of the corpus callosum.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.4 no.1
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• pp.5-12
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• 2004

Purpose Phenylketonuria is an inborn error of metabolism, which is inherited as an autosomal recessive trait. PKU is resulting from deficiency of phenylalanine hydroxylase. PAH gene spans about 90 kb on chromosome 12q and comprises 13 exons. In order to define the genetic basis of PKU and the frequencies and distribution of PAH mutations in the Korean population, we analyzed PAH gene in independent 80 patients with PKU. Methods All 13 exons including exon-intron boundaries and 2 kb of 5' upstream region of the PAH gene were analyzed by PCR-direct sequencing methods. Results PAH gene analysis revealed 39 different mutations including 10 novel mutations. The novel mutations consisted of 9 missense mutations (P69S, G103S, N207D, T278S, P281A, L293M, G332V, S391I and A447P) and a novel splice site variant (IVS10-3C>G). R243Q, IVS4-1G>A, and E6-96A>G were the most relevant mutations and they accounted in the whole for 38% of the mutant alleles identified in this study. We also observed that. $BH_4$ responsibility was. associated with genotype of R241C, R53H and R408Q. Conc1ustion Our present study with 80 participants extends the previous results to more comprehensive understanding of PAH allele distribution and frequency in Koreans. Although Korean mutation profile of PAH is similar to those of the nearest oriental populations (Japanese, Chinese, and Taiwanese), several different characteristic features are revealed. The characterization of the genotype-phenotype relationship was also performed. Our data would be very useful information for diagnosis, genetic counseling and planning of dietary and therapeutic strategies in Korean PAH patients.

• Journal of Genetic Medicine
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• v.17 no.2
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• pp.102-107
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• 2020

We report the case of an infant with a 4q35.1 deletion with 10p duplication. This mutation is rarely reported in the literature and has been found to have variable clinical findings, often including developmental delay. In this case, the condition was detected by chromosomal microarray analysis after initial manifestation of a feeding problem and developmental delay. Minor dysmorphic features with abnormal neurological examination led to further evaluation. The father's chromosome complement was 46, XY, t(4;10)(q35;p12.2). Parental balanced translocation can go unrecognized, because affected individuals are often phenotypically healthy until they have fertility issues such as recurrent miscarriages or children with severe congenital disorders. Genetic diagnoses help to establish a clear family genetic background that permits the development of clear treatment strategies. Prenatal counseling can also help to understand the possible risks associated with pregnancy or future child planning.

• Genomics & Informatics
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• v.20 no.3
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• pp.30.1-30.9
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• 2022

Hereditary spastic paraplegia is a not common inherited neurological disorder with heterogeneous clinical expressions. ALDH18A1 (located on 10q24.1) gene-related spastic paraplegias (SPG9A and SPG9B) are rare metabolic disorders caused by dominant and recessive mutations that have been found recently. Autosomal recessive hereditary spastic paraplegia is a common and clinical type of familial spastic paraplegia linked to the SPG11 locus (locates on 15q21.1). There are different symptoms of spastic paraplegia, such as muscle atrophy, moderate mental retardation, short stature, balance problem, and lower limb weakness. Our first proband involves a 45 years old man and our second proband involves a 20 years old woman both are affected by spastic paraplegia disease. Genomic DNA was extracted from the peripheral blood of the patients, their parents, and their siblings using a filter-based methodology and quantified and used for molecular analysis and sequencing. Sequencing libraries were generated using Agilent SureSelect Human All ExonV7 kit, and the qualified libraries are fed into NovaSeq 6000 Illumina sequencers. Sanger sequencing was performed by an ABI prism 3730 sequencer. Here, for the first time, we report two cases, the first one which contains likely pathogenic NM_002860: c.475C>T: p.R159X mutation of the ALDH18A1 and the second one has likely pathogenic NM_001160227.2: c.5454dupA: p.Glu1819Argfs Ter11 mutation of the SPG11 gene and also was identified by the whole-exome sequencing and confirmed by Sanger sequencing. Our aim with this study was to confirm that these two novel variants are direct causes of spastic paraplegia.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.08a
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• pp.55-67
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• 1999

A puc -deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under the light-limiting photoheterotrophic ( 3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R.sphaeroides SK101 was ioslate dto have∼40-h doubling at 3 Watts/㎡, while the growth of the mutant was not distinguished from its parental strain during both aerobic and light-saturating photoheterotrphic (10W/㎡) growth. The B875 complex of SK101 under the light-limiting conditions was elevated by 20 to 30% compared with that of the puc -deleted cell, reflecting parallel increase of bacteriochlorophyll and carotenoid contents of the mutant. The formation of B875 complex of SK101 under the anaerobic dark conditions with dimethylsulfoxide was the same as that of the puc-deleted cell. suggesting that the mutation of SK101 result in the altered control of B875 complex formation by light. When puc is restored in SK101 , it is not B875 complex but B800-850 complex which formation is elevated. The mutation of SK101 affected the bchF transcription most drastically to show two to tenfold increase during both aerobic and photoheterotrophic growth. The mutated phenotype of SK101 was complemented with pW2, which contains approximately 100-kb HNA of the photosynthetic gene clusters. The complementing DNA was narrowed down to a 1.1-kb DNA containing orfQ and pufKBA . The mutation of SK101 appeared to be exerted through the mutation of the orfQ gene encoding a putative bacteriochlorophyll -mobilizing protein.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.26-33
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• 2008

Purpose : Phenylketonuria(PKU) is an inborn error of metabolism and a genetic disorder resulting from a deficiency of phenylalanine hydroxylase(PAH) and decreased activity of tetrahydrobiopterin(BH4).In this study the correlation between the DNA mutation and clinical manifestations was investigated and PAH DNA mutations were compared bewteen Asian and Caucasian populations. Methods : DNA was isolated from peripheral leukocytes. The PAH gene was amplified by Polymerase Chain Reaction(PCR) and the sequence was analyzed with Multiplex Ligation-dependent Probe Amplification(MLPA). Results : We characterized the PAH gene of 102 independent Korean patients with PKU. PAH nucleotide sequence analysis revealed 44 different mutations, including 10 novel mutations comprising 9 missense mutations(N207D, K95del, A447P, G344D, P69S, S391I, A202T, G103S, and I306L) and 1 novel splice-site variant mutation(IVS10-3C>G). R243Q was the most prevalent mutation in this study. A259T has not previously been reported in Asian populations, but we found that this mutation had a frequency of 10.1% in our study. Furthermore, the genotypes of $BH_4$ responsive patients were analyzed and were divided into two groups: $BH_4$ medication-only group and $BH_4$ medication with diet therapy group. In the $BH_4$ medication-only group and $BH_4$ medication with diet therapy group, R241C was the most common mutation. Conclusion : Novel mutations in the PAH gene of PKU patients are still being discovered. Additional information as to the frequency of mutations in the tetrahydrobiopterine responsive gene is also accumulating. We anticipate that knowledge of these PKU gene mutations will assist the diagnosis, genetic counseling, and therapeutic treatment of PKU patients in future.

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.38-44
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• 2007

Purpose : Menkes disease is an X-linked recessively inherited disorder caused by the mutation of the ATP7A gene encoding copper-transporting P-type AT Pase. The phenotypic features are progressive neurological degeneration, mental retardation, loose skin, and vascular complications. Early diagnosis and treatment are very important for the prognosis of Menkes disease. Here, we describe nov el mutations of the ATP7A gene and prenatal diagnosis by mutation analysis. Methods : Five unrelated Korean Menkes patients were included in this study. They presented with depigmented wool-like hair, progressive neurologic deterioration, and hypotonia in infancy. Serum copper and ceruloplasmin levels w ere decreased. Brain magnetic resonance imaging revealed tortuous intracranial vessels. Mutation analysis has been carried out using cDNA from cultured skin fibroblasts or genomic DNA from peripheral leukocytes. Prenatal diagnosis was performed in two cases using chorionic villi samples or amniocytes. Results : Four novel mutations have been identified from four different families; c.3511+1G>A (p.E1099_N1171delinsMfsX 18), c.4005+5 G>A (p.V1268_R1335del), c.1870_2172del (p.S624_Q724del), and c.3352 G>A (p.G1118S). T he remaining one was previously reported (c.1933 C>T (p.V 1268_R1335del)). On prenatal DNA analysis, one w as diagnosed as normal, while the other turned out to be a female heterozygote with p.S624_Q724del mutation of the ATP7A gene. Conclusion : We identified 4 novel mutations of the ATP7A gene. Prenatal diagnosis in families at risk is critical in order to choose preventiv e options including an early treatment with copper-histidine therapy or therapeutic termination. Most mutations of the ATP7A gene were frame-shift mutations and prenatal diagnosis has been successfully carried out.

• Clinical and Experimental Pediatrics
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• v.57 no.1
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• pp.46-49
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• 2014

CHARGE syndrome has been estimated to occur in 1:10,000 births worldwide and shows various clinical manifestations. It is a genetic disorder characterized by a specific and a recognizable pattern of anomalies. The major clinical features are ocular coloboma, heart malformations, atresia of the choanae, growth retardation, genital hypoplasia, and ear abnormalities. The chromodomain helicase DNA-binding protein 7 (CHD7) gene, located on chromosome 8q12.1, causes CHARGE syndrome. The CHD7 protein is an adenosine triphosphate (ATP)-dependent chromatin remodeling protein. A total of 67% of patients clinically diagnosed with CHARGE syndrome have CHD7 mutations. Five hundred twenty-eight pathogenic and unique CHD7 alterations have been identified so far. We describe a patient with a CHARGE syndrome diagnosis who carried a novel de novo mutation, a c.3896T>C (p. leu1299Pro) missense mutation, in the CHD7 gene. This finding will provide more information for genetic counseling and expand our understanding of the pathogenesis and development of CHARGE syndrome.

• Journal of Genetic Medicine
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• v.17 no.2
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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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• v.18 no.1
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• pp.48-54
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• 2021

Genetic imbalances are a major cause of congenital and developmental abnormalities. We report the first case of a 3p26 microdeletion and 5q35.2q35.3 microduplication in a newborn with multiple congenital anomalies evaluated using chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH). The patient was born at 30 weeks and 2 days of gestation with a body weight of 890 g. He had symmetric intrauterine growth restriction, microcephaly, facial dysmorphism (hypertelorism, blepharophimosis, mild low-set ears, high-arched palate, and micrognathia), and right thumb polydactyly. Echocardiography revealed an atrial septal defect and patent ductus arteriosus. Furthermore, CMA revealed a concurrent microdeletion in 3p26 and a microduplication in 5q35.2q35.3. FISH analysis showed that these genetic changes resulted from a translocation mutation between chromosomes 3 and 5. The patient's mother had mild intellectual disability, short stature, and facial dysmorphism, while his father had a normal phenotype. However, parental FISH analysis revealed that the asymptomatic father carried a balanced translocation of chromosomes 3p26 and 5q35. CMA and FISH tests are useful for diagnosing neonates with multiple congenital abnormalities. Further parental genetic investigation and proper genetic counseling are necessary in cases of chromosomal abnormalities inherited from parental balanced translocations.