[Analysis of genome-wide copy number variations among fetuses with abnormalities detected by prenatal ultrasouography].

OBJECTIVE: To explore the genetic etiology of fetal abnormalities detected by prenatal ultrasound through single nucleotide polymorphism (SNP array) analysis.

METHODS: Two hundred and eight fetuses were tested with SNP array and conventional karyotyping. Complex copy number variations (CNVs) were verified with fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and quantitative fluorescence polymerase chain reaction (QF-PCR).

RESULTS: For the 208 cases, the diagnostic yields of conventional karyotping and SNP assay were 8.2%(17/208) and 13.9%(29/208), respectively. For fetuses with malformations of the cardiovascular system, central nervous system or multiple systems, pathogenic CNVs was detected in 4.6% (8/174), 2.3%(4/174), and 1.1% (2/174) of all fetuses, respectively. No pathogenic CNVs was detected among those with abnormalities of the renal system, digestive system, skeletal system, facial dysmorphism or respiratory system.

CONCLUSION: CNVs are significantly related with birth defects. Compared with conventional karyotyping, SNP array is a better platform for CNVs detection and can provide more clues for genetic counseling, recurrence risk assessment and prenatal diagnosis.