Diagnosis of a case with recurrent pregnancy loss resulted from maternal balanced translocation by chromosomal microarray analysis

Abstract

To explore the genetic basis for a couple with recurrent pregnancy loss by using single nucleotide polymorphism array (SNP array), chromosomal karyotype analysis, and fluorescence in situ hybridization (FISH). A SNP array was used for analyzing sample derived from the abortic tissue. The couple was analyzed with G-banded karyotyping and an Illumina Human CytoSNP-12 Beadchip assay. Based on the results, specific probes were designed to verify the chromosomal aberration by FISH. The SNP array showed a 16.6 Mb duplication at 11q23.3-q25 and a 11 Mb deletion at 15q26.1-q26.3 in the abortic tissue. Combined with high-resolution G-banding analysis, the karyotype of the wife was verified to be 46,XX,t(11;15)(q24;q26.2). FISH analysis using probes for 11pter/11qter and 15qter confirmed that she has carried a balanced translocation, while the fetus has carried a derivative chromosome 15 derived from the maternal translocation. SNP array can facilitate detection of balanced translocations which are difficult to be identified by conventional chromosomal karyotyping. The method does not necessitate cell culture and can well suit genetic analysis for couples with recurrent pregnancy loss.