Abstract

Detection of translocations in subtelomeric regions of chromosomes is a serious diagnostic problem, because they are difficult to determine by conventional cytogenetics with G banding. The aim of this work was the development of the technology of DNA probe synthesis for unique sequences of subtelomeric chromosome regions based on long-range PCR using the clinical case of determining the parental origin of unbalanced translocation between chromosomes 5 and 8. The unbalanced translocation der(5)t(5;8)(р15.33;q24.22) in a proband with physical, motor, intellectual, and speech development delay and in his sibling with speech and intellectual development delay as well, which was previously identified by array comparative genomic hybridization (aCGH), was confirmed by FISH. A balanced translocation 46,XX,t(5;8)(p15.33;q24.22) was detected in the mother’s karyotype using the created locus-specific DNA probe. This chromosome aberration was not detected by G banding of metaphase chromosomes. The father’s karyotype was normal according to FISH results. The method presented here makes it possible to create locus-specific DNA probes in a molecular cytogenetic laboratory using long-range PCR for the rapid diagnosis of cryptic chromosomal rearrangements.

中文翻译：

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基于长距离PCR的基因座特异性DNA探针合成技术对染色体易位的FISH诊断

摘要

染色体亚端粒区域中易位的检测是一个严重的诊断问题，因为很难用具有G条带的常规细胞遗传学来确定它们。这项工作的目的是开发基于长距离PCR的亚端粒染色体区域独特序列的DNA探针合成技术，该技术使用临床案例来确定5号和8号染色体之间不平衡易位的亲本起源。 （5）t（5; 8）（р15.33; q24.22）在具有身体，运动，智力和言语发展迟缓的先证者中，以及在其同伴中也存在言语和智力发展迟缓的先证者中，这先前已由FISH证实了阵列比较基因组杂交（aCGH）。平衡易位46，XX，t（5; 8）（p15.33; q24。22）使用创建的基因座特异性DNA探针检测到母亲的核型。中期染色体的G条带未检测到该染色体畸变。根据FISH结果，父亲的核型正常。此处介绍的方法可以使用远程PCR在分子细胞遗传学实验室中创建基因座特异性DNA探针，以快速诊断隐性染色体重排。