RESUMO
Objective To investigate the possibility and feasibility of the whole genome microarray scanning technique in clinical cytogenetic diagnosis of an uncertain karyotype and mentally retarded child. Methods The karyotype analysis of the mental development delayed child was 47, XY+mar. Genomic DNA was extracted from the peripheral blood and the whole genome microarray scanning technique was used to analyze the derivative chromosome. Results The whole genome microar-ray scanning technique indicated the derivative chromosome fragment had originated from 9p13.1-p24.3. Conclusions Com-paring to conventional cytogenetic analysis methods, the whole genome microarray scanning technique is of high resolution, high-throughput and high accuracy, which can detect the submicroscopic chromosomal aberrations and replace the conven-tional karyotype analysis.
RESUMO
Objective To understand genomic copy number variations (CNVs) and ascertain karyotype for a 46,X0, + der(?) fetus, and investigate possibility and superiority of array-based comparative genomic hybridization (array-CGH ) in clinical cytogenetic diagnosis. Methods G-banded chromosome analysis was carried out. The whole genome of the fetus was scanned and analysed by array-CGH. The results of array-CGH were confirmed by RT-qPCR. Results G-banded chromosome analysis showed that the fetal karyotype was 46,X0, +der(?). Array-CGH revealed the derivative chromosome as Y chromosome without CNVs. A total number of 118 submicroscopic CNVs were identified. Comparable results between array-CGH and RT-qPCR were obtained for 9 novel CNVs. Conclusion Comparing with conventional cytogenetic analysis, array-CGH is of high resolution, high-throughput and high accuracy, which provides a technical platform for accurate detection of submicroscopic chromosomal aberrations.