ABSTRACT
Objective@#To explore the clinical significance of a prenatal case with two small supernumerary marker chromosomes (sSMC) through identification of their origins.@*Methods@#G-banding chromosomal karyotyping analysis were carried out on fetal amniotic fluid sample and peripheral blood samples from both patients. Fluorescence in situ hybridization (FISH) and single nucleotide polymorphism-array (SNP-array) were used to analyze the component and size of the sSMCs.@*Results@#The karyotype of the fetus was determined as 47, XX, + mar[53]/48, XX, + 2 mar[31]/46, XX[14]. SNP-array has revealed four copies of chromosome 2q11.1q11.2 with a size of 2.6 Mb and three copies of 10p11.23q11.23 with a size of 20.6 Mb. The results was confirmed by FISH.@*Conclusion@#A rare chromosomal abnormality with two sSMCs was identified by combined karyotype analysis, SNP-array and FISH, which provided valuable information for prenatal diagnosis.
ABSTRACT
The combined array comparative genomic hybridization plus single-nucleotide polymorphism microarray (CGH+SNP microarray) platform can simultaneously detect copy number alterations (CNA) and copy-neutral loss of heterozygosity (LOH). Eighteen children with acute myeloid leukemia (AML) (n=15) or myelodysplastic syndrome (MDS) (n=3) were studied using CGH+SNP microarray to evaluate the clinical significance of submicroscopic chromosomal aberrations. CGH+SNP microarray revealed CNAs at 14 regions in 9 patients, while metaphase cytogenetic (MC) analysis detected CNAs in 11 regions in 8 patients. Using CGH+SNP microarray, LOHs>10 Mb involving terminal regions or the whole chromosome were detected in 3 of 18 patients (17%). CGH+SNP microarray revealed cryptic LOHs with or without CNAs in 3 of 5 patients with normal karyotypes. CGH+SNP microarray detected additional cryptic CNAs (n=2) and LOHs (n=5) in 6 of 13 patients with abnormal MC. In total, 9 patients demonstrated additional aberrations, including CNAs (n=3) and/or LOHs (n=8). Three of 15 patients with AML and terminal LOH>10 Mb demonstrated a significantly inferior relapse-free survival rate (P=0.041). This study demonstrates that CGH+SNP microarray can simultaneously detect previously cryptic CNAs and LOH, which may demonstrate prognostic implications.