• Clinical and Experimental Pediatrics
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• 제55권12호
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• pp.487-490
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• 2012

We report a case of isodicentric chromosome 15 (idic(15) chromosome), the presence of which resulted in uncontrolled seizures, including epileptic spasms, tonic seizures, and global developmental delay. A 10-month-old female infant was referred to our pediatric neurology clinic because of uncontrolled seizures and global developmental delay. She had generalized tonic-clonic seizures since 7 months of age. At referral, she could not control her head and presented with generalized hypotonia. Her brain magnetic resonance imaging scans and metabolic evaluation results were normal. Routine karyotyping indicated the presence of a supernumerary marker chromosome of unknown origin (47, XX +mar). An array-comparative genomic hybridization (CGH) analysis revealed amplification from 15q11.1 to 15q13.1. Subsequent fluorescence in situ hybridization analysis confirmed a idic(15) chromosome. Array-CGH analysis has the advantage in determining the unknown origin of a supernumerary marker chromosome, and could be a useful method for the genetic diagnosis of epilepsy syndromes associated with various chromosomal aberrations.

• Journal of Genetic Medicine
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• 제14권1호
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• pp.43-47
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• 2017

Cat eye syndrome (CES) is a very rare chromosomal syndrome characterized by various malformations such as anal atresia, preauricular malformation, coloboma of the iris, and congenial heart and renal defects. This genetic disorder is caused by partial duplication of chromosome 22, mostly as a result of a supernumerary isodicentric marker chromosome idic(22)(q11.2). Various congenital abnormalities and extreme phenotypic variability in CES patients have been reported, which have made prenatal diagnosis of CES difficult. We report the first case diagnosed with CES prenatally by multiplex ligation-dependent probe amplification in a woman who was referred to our hospital, for a fetus presenting with heart anomaly.

• Journal of Genetic Medicine
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• 제8권2호
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• pp.119-124
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• 2011

목적: 표지염색체(supernumerary marker chromosome, SMC)는 유래한 염색체에 따라서 임상 증상이 다양하다. 본 연구는 염색체 마이크로어레이를 이용하여 SMC의 기원을 밝히고 각 증례마다 분자세포유전학적 특성과 임상 표현형을 분석하고자 하였다. 대상 및 방법: 염색체 검사에서 SMC가 검출된 환자들 중에서 15번 염색체 유래를 제외한 4명의 환자에서 CGH 기법의 올리고 뉴클레오티드 염색체 마이크로어레이를 시행하였다. 결과: 3명의 환자에서 유래된 염색체 부위를 확인할 수 있었다. 증례1은 1q21.1-q23.3에서 16.1 Mb의 SMC를 가졌고, 증례2는 19p13.11-q13.12에서 21 Mb, 증례3은 22q11.1-q11.21과 22q11.22-q11.23의 두 구간에서 각각 2.5Mb와 2.0Mb로 재배열된 4.5 Mb의 SMC를 나타내었다. 결론: 증례1은 1q21.1 중복증후군을 포함하여 광범위한 임상표 현형을 나타내었다. 증례2는 아스퍼거 증후군과 유사한 정신행동 이상 소견은 19p12-q13.11, 청력장애와 사시는 19p13.11, 그 외 증상은 19q13.12의 유전자와 연관 가능성이 높다. 증례３은 묘안 증후군 type I 및 22q11.2 미세중복증후군과 비교했을 때 항문폐쇄는 22q11.1-q11.21, 그 외 증상들은 22q11.22-q11.23과 연관성을 시사하였다. 고해상도 염색체 마이크로어레이 분석은 SMC의 유래를 확인할 수 있고 유전형-표현형 상관성을 이해함으로써 유전상담에 도움이 된다.

• 대한의생명과학회지
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• 제17권2호
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• pp.129-134
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• 2011

Mosaicism is the presence of two or more chromosomally distinct cell lines, each seen in two or more cells. Chromosomal mosaicism presents one of the most difficult problems in prenatal cytogenetic diagnosis, requiring the differentiation of true mosaicism from pseudomosaicism. To overcome associated problems we investigated 24 cases (amniotic fluid 13 cases, abortus tissue 3 cases, peripheral blood 8 cases) in which mosaicism has been found in cytogenetic analysis. 5 cases (38.5%) of 13 amniotic fluid cells in which mosaicisms showed single cell pseudomosaicism. Chromosomal true mosaicism is found in about 0.28% (8/2,826) of amniotic fluid cell cultures. The 24 cases involved 12 cases (50%) with sex chromosomal abnormalities, 7 cases (29.2%) with autosomal structural defects, 3 cases (12.5%) with autosomal abnormalities, 2 cases (8.3%) with a supernumerary marker. Mosaicism detected in amniotic fluid may represent the true mosaicism or may pseudomosaicism. If the same chromosome abnormality is seen in more than one cell and in two different cultures, it is considered a true mosaicism, whereas single-cell abnormalities from a single culture are regarded as pseudomosaicism. In this study, we describe a mosaicism in chromosome analysis, its diagnostic problems and clinical significance.