Application for prenatal diagnosis using both chromosomal karyotype analysis and BACs-on-Beads assay / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the application value in prenatal diagnosis using karyotype analysis combined with BACs-on-Beads (BoBs) assay.</p><p><b>METHODS</b>Nine hundred sixty five pregnant women were subjected to amniocentesis, chromosomal karyotype analysis and detection of BoBs were employed simultaneously for abnormal number of chromosomes and 9 chromosome microdeletion syndrome in prenatal diagnosis.</p><p><b>RESULTS</b>Fifty cases common chromosome aneupoidies were successfully detected by both karyotype analysis and BoBs which included 31 cases of trisomy 21,10 cases of trisomy 18 and 9 cases with sex chromosome abnormality. BoBs in addition detected 1 case of DiGeorge-1 microdeletion syndrome and 1 case of 7q11.23 microduplication syndrome. All 9 fetuses with chromosome abnormalities detected by karyotyping were missed by BoBs, including 2 cases of marker chromosomes,4 cases of chromosomal translocation,1 case of chromosomal inversion, 2 cases of Sex chromosome mosaicism; 2 cases of fetal inherited from the parents,7 cases for novel mutations.</p><p><b>CONCLUSION</b>Karyotype analysis combined with BoBs dedtection is a rapid, effective and highly accurate prenatal diagnosis model that may should be widely used in clinical diagnosis.</p>

Prenatal diagnosis of a rare case of 7q11.23 duplication syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the application of combined techniques for the prenatal diagnosis of a case with 7q11.23 duplication.</p><p><b>METHODS</b>Amniocentesis was performed in the second trimester for a mother with a high risk suggested by serological prenatal screening. G-banded chromosomal analysis was performed on cultured amniocytes and peripheral blood samples from both parents. DNA from amniotic fluid sample was isolated for a BACs-on-Beads (BoBs) assay. To define the range of duplication, copy number variation was determined with single nucleotide polymorphism array (SNP array, Affymetrix CytoScan 750K) and fluorescence in situ hybridization (FISH) analysis.</p><p><b>RESULTS</b>Chromosomal analysis suggested that the fetus and both parents all had a normal karyotype, while a duplication of 7q11.23 was detected by the BoBs assay. SNP array revealed a 1.5 Mb duplication in chromosome 7q11.23, which was confirmed by FISH.</p><p><b>CONCLUSION</b>Combined prenatal BoBs, SNP array and FISH has enabled effective diagnose of a case with 7q11.23 syndrome.</p>