OBJECTIVETo assess the clinical application of single nucleotide polymorphism (SNP)-array in detecting abnormal chromosome karyotypes of chorionic villi from early spontaneous abortuses.

METHODSA total of 861 chorionic villus samples from unexplained early spontaneous abortion were collected from Women's Hospital, Zhejiang University School of Medicine during October 2013 and June 2016, and SNP-array was performed to detect genome-wide DNA copy number variants.

RESULTSAll samples were successfully tested by SNP-array and 440 cases (51.10%) were found to have abnormal chromosome constitutions. Aneuploidy was identified in 358 (41.58%) cases, distributing in all chromosomes except chromosome 1. Triploidy and haploidy were found in 21 (2.44%) and one case (0.12%), respectively. Thirty-seven cases (4.30%) were identified as single chromosomal segment deletion or duplication, 25 of which were less than 10 Mb in size. For 6 of 25 cases with unclear pathogenesis, family studies were carried out to identify origin of deletion or duplication, showing that 4 cases were de novo and 2 were inherited from one of the parents. Twenty-three cases (2.67%) showed two chromosomal deletion/duplication segments. Combining with karyotyping and fluorescencehybridization, 6 cases were identified as de novo aberration and 11 carried small-size segmental balanced abnormality.

CONCLUSIONSSNP-array can provide a relatively comprehensive genetic analysis of chorionic villi and can detect various kinds of chromosome abnormalities in spontaneous miscarriages.