• Genomics & Informatics
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• 제9권2호
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• pp.64-68
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• 2011

Monomelic amyotrophy (MA), also known as Hirayama disease, occurs mainly in young men and manifests as weakness and wasting of the muscles of the distal upper limbs. Here, we sought to identify a genetic basis for MA. Given the predominance of MA in males, we focused on candidate neurological disease genes located on the X chromosome, selecting two X-linked candidate genes, androgen receptor (AR ) and ubiquitin-like modifier activating enzyme 1 (UBA1). Screening for genetic variants using patients' genomic DNA revealed three known genetic variants in the coding region of the AR gene: one nonsynonymous single-nucleotide polymorphism (SNP; rs78686797) encoding Leu57Gln, and two variants of polymorphic trinucleotide repeat segments that encode polyglutamine (CAG repeat; rs5902610) and polyglycine (GGC repeat; rs3138869) tracts. Notably, the Leu57Gln polymorphism was found in two patients with MA from 24 MA patients, whereas no variants were found in 142 healthy male controls. However, the numbers of CAG and GGC repeats in the AR gene were within the normal range. These data suggest that the Leu57Gln polymorphism encoded by the X-linked AR gene may contribute to the development of MA.

• Journal of Genetic Medicine
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• 제4권1호
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• pp.22-37
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• 2007

The autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases, clinically and genetically heterogeneous, characterized by degeneration of spinocerebellar pathways with variable involvement of other neural systems. At present, 27 distinct genetic forms of SCAs are known: SCA1-8, SCA10-21, SCA23, SCA25-28, DRPLA (dentatorubral-pallidoluysian atrophy), and 16q-liked ADCA (autosomal dominant cerebellar ataxia). Epidemiological data about the prevalence of SCAs are restricted to a few studies of isolated geographical regions, and most do not reflect the real occurrence of the disease. In general a prevalence of about 0.3-2 cases per 100,000 people is assumed. As SCA are highly heterogeneous, the prevalence of specific subtypes varies between different ethnic and continental populations. Most recent data suggest that SCA3 is the commonest subtype worldwide; SCA1, SCA2, SCA6, SCA7, and SCA8 have a prevalence of over 2%, and the remaining SCAs are thought to be rare (prevalence <1%). In this review, we highlight and discuss the SCA7. The hallmark of SCA7 is the association of hereditary ataxia and visual loss caused by pigmentary macular degeneration. Visual failure is progressive, bilateral and symmetrical, and leads irreversibly to blindness. This association represents a distinct disease entity classified as autosomal dominant cerebellar ataxia (ADCA) type II by Harding. The disease affectsprimarily the cerebellum and the retina by the moderate to severe neuronal loss and gliosis, but also many other central nervous system structures as the disease progresses. SCA7 is caused by expansion of an unstable trinucleotide CAG repeat in the ATXN7 gene encoding a polyglutamine (polyQ) tract in the corresponding protein, ataxin-7. Normal ATXN7 alleles contain 4-35 CAG repeats, whereas pathological alleles contain from 36->450 CAG repeats. Immunoblott analysis demonstrated that ataxin-7 is widely expressed but that expression levels vary among tissues. Instability of expanded repeats is more pronounced in SCA7 than in other SCA subtypes and can cause substantial lowering of age at onset in successive generations termed ‘anticipation’ so that children may become diseased even before their parents develop symptoms. The strong anticipation in SCA7 and the rarity of contractions should have led to its extinction within a few generations. There is no specific drug therapy for this neurodegenerative disorder. Currently, therapy remains purely symptomatic. Cellular models and SCA7 transgenic mice have been generated which constitute valuable resources for studying the disease mechanism. Understanding the pathogenetic mechanisms of neurodegeneration in SCAs should lead to the identification of potential therapeutic targets and ultimately facilitate drug discovery. Here we summarize the clinical, pathological, and genetic aspects of SCA7, and review the current understanding of the pathogenesis of this disorder. Further, we also review the potential therapeutic strategies that are currently being explored in polyglutamine diseases.

• Clinical and Experimental Pediatrics
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• 제50권9호
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• pp.868-874
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• 2007

목 적 : 선천성 근육긴장성 이영양증(congenital myotonic dystrophy, CDM) 환자의 주산기 병력, 영아기 및 소아기의 증상, 그리고 환자 어머니의 임상양상을 확인하여, 임상진단에 도움이 될 수 있는 특징적인 소견과, DMPK유전자의 CTG 서열반복 수와 운동발달 관계를 확인하고자 하였다. 방 법 : 2001년 1월부터 2006년 9월까지 삼성서울병원에서 DMPK 유전자 검사를 통해 CDM으로 확진된 환자 8명(남자 2명, 여자 8명)을 대상으로 의무기록과 DMPK 유전자 검사를 후향적으로 분석하였다. 결 과 : 진단 시 환자들의 연령은 7일에서 45개월(중앙값: 20.5 개월)이었으며, 환자들은 발달지연, 수유곤란, 그리고 근육긴장저하를 주소로 내원하였다. 3명의 환자에서 산전 초음파 상 원인 불명의 양수과다증이 확인되었다. 모든 환자에서 운동발달지연이 있었으며, 연령이 증가할수록 호전되었다. 모든 환자들의 어머니에서 전형적인 근병증의 모습과 근육긴장증을 확인하였고, 4명의 환자에서는 어머니 형제의 가족력을 확인하였다. DMPK유전자의 CTG 서열반복 수는 1,000-2,083(중앙값: 1,533.5)의 분포를 보였으며, 운동발달 중 혼자 걷기의 지연 정도와 유의한 상관관계는 없었다. 1명의 환자에서 세대간 예견효과를 확인하였다. 결 론 : CDM 환자는 산전초음파에서 양수과다증, 내반첨족, 태동의 저하 등의 소견을 보이고, 출생 후 근육긴장저하와 연관된 호흡곤란, 수유곤란, 그리고 발달지연 등의 증상을 나타낸다. 모든 환자들의 어머니는 특징적인 근병증의 외양과 근육긴장증을 가지고 있어, 산모에 대해 이러한 소견을 확인하는 것이 산전진단에 중요한 단서가 된다. CDM에서 근육긴장저하와 연관된 증상은 연령이 증가할수록 호전되며, DMPK 유전자의 CTG 서열반복 수와 운동발달 중 혼자 걷기 시기 간의 유의한 연관은 없었다.

• Journal of Genetic Medicine
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• 제13권1호
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• pp.14-19
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• 2016

Purpose: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. Materials and Methods: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. Results: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. Conclusion: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.

• 한국해양생명과학회지
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• 제6권1호
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• pp.38-46
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• 2021

꼬막 종류 중 하나인 Tegillarca granosa는 해양 이매패류로서 한국, 중국, 일본 등의 중요한 수산 자원 중 하나이다. 꼬막의 염색체 수는 2n=38로 알려져 있지만, 유전체의 크기와 유전 정보에 대해서는 아직 명확하게 알려져 있지 않다. 꼬막의 유전체 크기 예측을 위하여 NGS Illumina HiSeq 플랫폼을 이용하여 얻은 짧은 DNA 서열 정보를 통하여 in silico 분석으로 유전체 크기를 분석하였다. 그 결과 꼬막의 유전체 크기는 770.61 Mb로 예측되었다. 이후 MaSuRCA assembler를 통하여 드래프트 게놈 조립 작업을 수행하고, QDD pipeline을 이용하여 SSR (simple sequence repeats) 분석을 수행하였다. 꼬막의 유전체로부터 43,944개의 SSR을 발굴하였으며, 다이-뉴클레오타이드(di-nucleotide) 69.51%, 트라이-뉴클레오타이드(tri-nucleotide) 16.68%, 테트라-뉴클레오타이드(tetra-nucleotide) 12.96%, 펜타-뉴클레오타이드(penta-nucleotide) 0.82% 그리고 헥사-뉴클레오타이드(hexa-nucleotide) 0.03%로 구성되었다. 이후 꼬막의 유전적 다양성 연구에 활용할 수 있는 100개의 마이크로새틀라이트 마커의 프라이머 세트를 선별하였다. 앞으로 이번 연구를 통해서, 꼬막의 집단유전학적 연구와 유전적 다양성을 규명하는데 도움이 될 것이며, 나아가 동종들 간의 원산지 분류를 알아낼 수 있을 것이다.