[Single nucleotide polymorphism-array in genetic analysis of chorionic villi from early spontaneous miscarriages].

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

METHODS: A 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.

RESULTS: All 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 fluorescence in situ hybridization, 6 cases were identified as de novo aberration and 11 carried small-size segmental balanced abnormality.

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