Abstract:Objective In order to provide references for the genetic counselling and clinical explanations of chromosome mosaicism, our research analyzed the prenatal diagnosis and pregnancy outcomes in 205 cases with mosaicism in amniotic fluid cells. Methods We retrospectively studied the resampling karyotypes and copy number variations sequencing (CNV-seq) results of the mosaicism cases in the Department of clinical genetics, Shengjing Hospital of China Medical University from Jan 2018 to Nov 2019, and several pregnancy outcomes were followed up. Results 205 mosaicism cases were found in a total of 7225 cases, with the rate of 2.8%. Among them, 153 (74.6%) cases and 18 (8.8%) cases were classified as level Ⅰ and level Ⅱ mosaicism separately, and level Ⅲ mosaicism was considered in the remaining 34 cases (16.6%). Most of levelⅠmosaicism cases were mosaic autosomal aneuploids, and mosaic sex chromosome aneuploids were majorities in level Ⅱ and level Ⅲ mosaicism. 20 patients underwent resampling, in which normal karyotypes were separately diagnosed in 14 cases with level Ⅰand 2 cases with levelⅡmosaicism, and 2 cases with level Ⅲ mosaic sex chromosome aneuploids; level Ⅲ was re-identified in one case with levelⅡ mosaic autosomal aneuploids. CNV-seq was performed in 76 cases and mosaicism was not detected in 53 cases with level Ⅰmosaicism. With the comparison between karyotypes and CNV-seq results, we found that CNV-seq couldn't detect the mosaicism in all of cases, and the constitutions of mosaicism were not entirely consistent. Conclusion The authenticity of level Ⅰand level Ⅲ mosaicism could be almost ascertained, and the subsequent options on level Ⅱmosaicism should be evaluated comprehensively. The mosaicism could be missed by the single application of CNV-seq and the usage of karyotype was irreplaceable. The combination of multiple methods were useful for judging the mosaicism rapidly and accurately.
赵小秋, 崔婉婷. 205例羊水细胞嵌合体的产前诊断结果分析[J]. 中国生育健康杂志, 2022, 33(1): 18-22.
ZHAO Xiaoqiu, CUI Wanting. Analysis of prenatal diagnosis outcomes of 205 cases with mosaicism in amniotic fluid cells. Chinese Journal of Reproductive Health, 2022, 33(1): 18-22.
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