Chromosomal abnormalities are a common cause of spontaneous abortions, but conventional detection methods (karyotype, FISH, and chromosomal microarray [CMA]) have limitations, and many cryptic balanced chromosomal rearrangements are difficult to detect. We describe a couple who experienced a missed abortion, studied by CMA. CMA of the abortion tissue detected a 1.62-Mb duplication at 14q11.2 and a 5.09-Mb deletion at 21q11.2q21.1, while the couple seemed to have a normal karyotype. Combining the results of CMA, whole-genome sequencing (WGS) breakpoint analysis, Sanger sequencing, and FISH, we found that the father was a 46,XY,t(14;21)(q11.2;q21.1) balanced translocation carrier. Our results indicate that WGS is an efficient and accurate approach to map breakpoints of cryptic reciprocal balanced translocations undetectable by standard karyotype.
Keywords: Balanced translocation; Chromosomal aberrations; Next-generation sequencing; Spontaneous abortion; Whole-genome sequencing.
© 2023 S. Karger AG, Basel.