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Background: Cytomolecular genetic laboratory techniques have developed from conventional G-banding karyotyping to whole genome sequencing. Although resolution has greatly increased, various cytogenetic techniques have their advantages and limitations in detecting genomic variations. Methods: We compared the chromosomal abnormalities detected by G-banding karyotyping and SNP-based microarray testing in 62 patients from July 2020 to December 2022. We analyzed their difference according to chromosomal abnormalities, including numerical and structural and others. Results: Of the 62 patients, 28 patients showed chromosomal aberration detected in one or more of the two test methods. Aneuploidy was detected in both methods, while gain and loss less than 3 Mb were only detectable by the microarray. G-banding karyotyping is fundamental to detect structural chromosome rearrangement such as inversions, ring chromosomes, and translocations, but additional breakpoint or unknown origin materials information obtained from microarray. Loss of heterozygosity was only detectable in microarray, and mosaicism had limitations in both G-banding karyotyping and microarray. Conclusions: Various disease cause genomic structural variants, it is very important to detect this. We showed discordance between G-banding karyotyping and SNP based microarray in clinical laboratory. It can be helpful to clinical physicians to decide which diagnostic tool to use. [ABSTRACT FROM AUTHOR]

Background: For HLA genotyping, PCR sequence-specific oligonucleotide (SSO) methods using the Luminex platform are widely used. We evaluated the performance of LabType-SSO (One Lambda, USA) in Koreans. Methods: LabType-SSO were performed on 50 residual DNA samples analyzed by sequence-based typing (SBT) for all HLA-A, -B, -C, -DRB1, and -DQB1 alleles with gene frequency > 0.1% in Koreans. Results: The LabType-SSO results were in complete agreement with SBT at the 2-digit level. For 4-digit level, 9 HLA-A alleles, 1 HLA-B allele, 3 HLA-C alleles, neither HLA-DRB1 nor -DQB1 allele showed ambiguous results for assignment of most probable types considering HLA gene frequency in Koreans. In addition, two cases of DQB1*04:01 allele were incorrectly assigned to DQB1*04:02. Conclusions: LabType-SSO tests showed accurate assignment of 2-digit level and LabType-SSO HLA-DRB1 test showed correct 4-digit most probable HLA type. The tests can be useful as intermediate resolution typing for solid organ transplantation. [ABSTRACT FROM AUTHOR]