• Journal of Genetic Medicine
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• 제16권1호
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• pp.27-30
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• 2019

Smith-Kingsmore syndrome (SKS; OMIM 616638), also known as macrocephaly-intellectual disability-neurodevelopmental disorder-small thorax syndrome (MINDS; ORPHA 457485), is a rare autosomal dominant disorder, the prevalence of which is not known. It is caused by a heterozygous germline mutation in MTOR (OMIM 601231). Ten different MTOR germline mutations in 27 individuals have been reported in the medical literature to date. These were all gain-of-function missense variants, and about half of the 27 individuals had c.5395G>A p.(Glu1799Lys) in MTOR. Here, I report for the first time a Korean patient with the heterozygous germline mutation c.5395G>A p.(Glu1799Lys) in MTOR. It was found to be a de novo mutation, which was identified by whole-exome sequencing and confirmed by Sanger sequencing. The patient showed typical clinical features of SKS, including macrocephaly/megalencephaly; moderate intellectual disability; seizures; behavioral problems; and facial dysmorphic features of curly hair, frontal bossing, midface hypoplasia, and hypertelorism.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권3호
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• pp.178-181
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• 2022

Williams-Beuren syndrome (WS) is a rare genetic disorder that results from microdeletion at chromosome 7, which harbors the elastin gene. Clinical findings include arteriopathy, aortic stenosis, hypertension, and laxities and contractures in different joints throughout the body. While many components of the temporomandibular joint (TMJ) normally contain elastin, there are few reports on TMJ manifestations of WS. This study reports a TMJ ankylosis case in a WS patient and shares insight on a possible link between development of TMJ ankylosis and elastin deficiency in WS patients. A WS patient presented with bilateral TMJ ankylosis and was successfully treated with TMJ gap arthroplasty. Hypermobility of TMJ and lack of elastin in retrodiscal tissue can induce anterior disc displacement without reduction. Due to lack of elastin, which has a significant role in the compensatory and reparatory mechanism of TMJ, WS patients might be prone to TMJ ankylosis.

• Journal of Genetic Medicine
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• 제20권2호
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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.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제20권2호
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• pp.114-123
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• 2017

Purpose: The goal of this study was the early diagnosis of ABCB11 spectrum liver disorders, especially those focused on benign recurrent intrahepatic cholestasis and progressive familial intrahepatic cholestasis. Methods: Fifty patients presenting neonatal cholestasis were evaluated to identify underlying etiologies. Genetic analysis was performed on patients suspected to have syndromic diseases or ABCB11 spectrum liver disorders. Two families with proven ABCB11 spectrum liver disorders were subjected to genetic analyses to confirm the diagnosis and were provided genetic counseling. Whole exome sequencing and Sanger sequencing were performed on the patients and the family members. Results: Idiopathic or viral hepatitis was diagnosed in 34%, metabolic disease in 20%, total parenteral nutrition induced cholestasis in 16%, extrahepatic biliary atresia in 14%, genetic disease in 10%, neonatal lupus in 2%, congenital syphilis in 2%, and choledochal cyst in 2% of the patients. The patient with progressive familial intrahepatic cholestasis had novel heterozygous mutations of ABCB11 c.11C>G (p.Ser4*) and c.1543A>G (p.Asn515Asp). The patient with benign recurrent intrahepatic cholestasis had homozygous mutations of ABCB11 c.1331T>C (p.Val444Ala) and heterozygous, c.3084A>G (p.Ala1028Ala). Genetic confirmation of ABCB11 spectrum liver disorder led to early liver transplantation in the progressive familial intrahepatic cholestasis patient. In addition, the atypically severe benign recurrent intrahepatic cholestasis patient was able to avoid unnecessary liver transplantation after genetic analysis. Conclusion: ABCB11 spectrum liver disorders can be clinically indistinguishable as they share similar characteristics related to acute episodes. A comprehensive genetic analysis will facilitate optimal diagnosis and treatment.

• Journal of Genetic Medicine
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• 제19권2호
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• pp.85-93
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• 2022

Purpose: Cornelia de Lange syndrome (CdLS) is a rare genetically heterogeneous disorder caused by genetic variants of the cohesin complex. However, the diverse genetic etiologies and their phenotypic correlations in Korean patients with CdLS are still largely unknown. Hence, this study aimed to clarify the clinical characteristics and genetic background of Korean patients with CdLS. Materials and Methods: The medical records of 15 unrelated patients (3 males and 12 females) genetically confirmed to have CdLS were retrospectively reviewed. All individuals were diagnosed with CdLS using target gene analysis, whole-exome sequencing, and/or chromosomal microarray analysis. The clinical score (CS) was calculated to assess disease severity. Results: The median age at diagnosis was 1.7 (range, 0.0-11.8) years, and median follow-up duration was 3.8 (range, 0.4-11.7) years. Eight (53.3%) patients showed classic phenotypes of CdLS, two (13.3%) showed non-classic phenotypes, and five (33.3%) had other phenotypes sharing limited signs of CdLS. Fifteen causative variants were identified: NIPBL in five (33.3%, including 3 males), SMC1A in three (20.0%), SMC3 in three (20.0%), and HDAC8 in four (26.7%) patients. The CS was significantly higher in the NIPBL group than in the non-NIPBL group (14.2±1.3 vs. 8.7±2.9, P<0.001). Conclusion: We identified the clinical and genetic heterogeneity of CdLS in Korean patients. Patients with variants of NIPBL had a more distinctive phenotype than those carrying variants of other cohesin complex genes (SMC1A, SMC3, and HDAC8). However, further studies are warranted to understand the pathogenesis of CdLS as a cohesinopathy and its genotype-phenotype correlations.

• Journal of Genetic Medicine
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• 제7권2호
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• pp.125-132
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• 2010

목 적: 착상전 유전진단(preimplantation genetic diagnosis, PGD)은 유전질환을 가진 부부들을 대상으로 체외수정을 통해 획득한 배아에서 유전진단을 하는 방법이다. 다양한 유전질환을 가진 부부에게 그 질환에 맞는 PGD의 설계가 진행되어야 하기 때문에 PGD 시행 전유전상담을 시행하는 것은 PGD 설계에 있어서 매우 중요하다. 이에, PGD 시행 시 필요한 유전상담의 내용에 대해 환자 및 가족과 전문가의 구체적인 의견을 수렴하고 분석하고자 하였다. 대상 및 방법: 본 연구는 PGD에 있어서 유전상담의 필요성과 중요성에 대한 의견을 알아보고자, 2010년 2월 3일부터 4월 30일까지 PGD를 실시 또는 실시 예정인 부부들과 PGD 관련 전문가들을 대상으로 이메일과 직접 설문지를 배포하여 설문조사를 실시하였다. 결 과: 환자 60명과 전문가 31명을 포함하여 총 91명이 설문조사에 응답하였으며, 환자들은 염색체 이상 질환 49명(81.7%)과 단일유전자 이상 질환 11명(18.3%) 이었다. 설문에 응답한 환자와 전문가 모두 유전상담이 PGD의 의료서비스 일환으로 반드시 필요하다고 답하였다. 환자의 충분한 이해를 위하여 필요한 유전상담의 시간에 대해 환자와 가족 그리고 전문가 의견을 수렴한 결과, 각각 45명(75.0%)과 23명(74.2%)이 적정한 유전상담시간을 30분 이상이라고 응답하였다. 하지만, 현 의료시스템에서는 짧은 진료시간 내 진료와 유전상담을 동시에 진행함으로써 환자에게 완벽한 정보제공이 이루어지지 않는 것으로 나타났다. 한편, 전문가 그룹에서는 진료시간의 부족과 유전질환의 정보 부족이 유전상담의 어려운 점이라고 답하였으며, 이에 비 의사(non-MD) 전문유전상담사가 필요하다는 의견이 30명(96.7%)으로 높게 나타났다. 환자와 가족들은 PGD 시술 시 예기치 못한 결과의 가능성, 환자가 가진 유전질환의 위험을 예방할 수 있는 선택사항, 환자가 가지고 있는 유전질환의 위험도 평가, 유전자 검사 시 검사의 목적 설명 및 검사기술의 한계점과 오진률의 설명, PGD 시술 전반에 관한 기술적인 정보 등에 대하여 관심을 가지고 있으며 더 자세한 설명을 필요로 하는 것으로 나타났다. 이에 대한 전문가 의견 역시 환자 및 가족이 관심 있고 자세한 설명을 원하는 정보와 대부분 일치하였다. 이에 따라 환자의 요구와 의견으로 나타난 위의 결과들을 향후 PGD를 위한 유전상담의 지침(guide-line) 구축 시 반영하여야 할 것으로 사료된다. 결 론: 본 연구에서 유전진단과 생식의학 기술의 발전과 더불어 PGD의 적용과 효율성 등에 대한인식이 높아짐에 따라, PGD를 시행함에 있어서 구체적이고 체계적인 유전상담이 필요하다는 것을 확인할 수 있었다. 본 연구의 설문조사 결과가 향후 PGD를 위한 유전상담 지침서(guideline)에 반영되어 적절한 PGD의 설계, 실시, 사후관리에 큰 도움이 되기를 기대한다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제11권sup1호
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• pp.72-82
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• 2008

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism that results in accumulation of copper primarily in the liver, the brain and the cornea. Mutations in the WD gene, ATP7B cause failure of copper excretion from hepatocyte into bile and a defective synthesis of ceruloplasmin. More than 370 mutations are now recognized, scattering throughout the ATP7B gene. Since WD has protean clinical presentations, awareness of WD in clinical practice is important for the early diagnosis and prevention of accumulated copper toxicity. None of the laboratory parameters alone allows a definite diagnosis of WD. There are numerous pitfalls in the diagnosis of WD. Low serum ceruloplasmin concentrations, increased 24 hour urinary copper excretion, increased hepatic copper concentrations and the presence of Kayser-Fleischer rings in the cornea are major diagnostic points. A combination of any two of these 4 laboratory findings is strong support for a diagnosis of WD. Molecular methods are now being used to aid diagnosis. Molecular genetic testing has confirmed the diagnosis in individuals in whom the diagnosis is not clearly established biochemically and clinically. Siblings should be screened for WD once an index case has been diagnosed. Discrimination of heterozygotes from asymptomatic patients is essential to avoid inappropriate lifelong therapy for heterozygotes. Genetic testing, either by haplotype analysis or by mutation analysis, is the only reliable tool for differentiating heterozygote carriers from affected asymptomatic patients. Currently, genetic testing is of limited value in the primary diagnosis. However, genetic testing will soon play an essential role in diagnosing WD as rapid advancement of biomedical technology will allow more rapid, easier and less expensive mutation detection.

• Journal of Interdisciplinary Genomics
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• 제2권2호
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• pp.13-17
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• 2020

Infantile nystagmus syndrome (INS) is a genetically heterogeneous disorder. To date, more than 100 genes have been reported to cause INS and there is significant overlap in phenotypic characteristics. The most common form of X-linked INS is attributed to FRMD7 at Xq26. Recent advances in molecular genetics have facilitated the identification of pathogenic variants of FRMD7 and the investigation for underlying mechanisms of FRMD7-associated INS. This review summarizes genetic and clinical features of FRMD7-associated INS, and introduces updates on the pathogenesis of FRMD7 mutation.

• Journal of Genetic Medicine
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• 제4권2호
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• pp.115-121
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• 2007

Hereditary motor and sensory neuropathy (HMSN; Charcot-Marie-Tooth disease, CMT) was first described by Charcot and Marie in France and, independently, by Tooth in England in 1886. HMSN is the most common form of inherited motor and sensory neuropathy, and is a genetically heterogeneous disorder of the peripheral nervous system. Using positional cloning methods, the chromosomal localization (locus) of more than 40 inherited peripheral neuropathies was found in the last 15 years. However, these genetic analyses also show that many entities do not show linkage to the known loci. This issue deals with a clinical survey of inherited peripheral neuropathies regarding diagnostic approaches based on the molecular findings.

• Journal of Interdisciplinary Genomics
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• 제2권1호
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• pp.10-12
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• 2020

Coffin-Lowry syndrome (CLS) is a genetic disorder characterized by intellectual disability, typical facial features, and skeletal abnormalities. But this syndrome shows highly variable clinical manifestations, and can't be diagnosed with conventional chromosome analysis or comparative genomic hybridization, leading to delayed diagnosis. Here we report an 18-year-old boy with CLS diagnosed by whole exome sequencing. Our patient initially presented with developmental delay, facial dysmorphism at the age of 1. At the age of 18, he developed orthopnea due to mitral regurgitation. At the 22 years of age, he was diagnosed as CLS diagnosed by whole exome sequencing. Our case implies that clinical suspicion is important for early diagnosis, and advanced diagnostic tools such as WES should be considered in suspected cases.