ABC | Volume 111, Nº4, Octuber 2018

Original Article Luo et al Genetic testing analysis of fetuses with CHD Arq Bras Cardiol. 2018; 111(4):571-577 Figure 1 – The patient pathway in the current study. PND: perinatal deaths. CMA: chromosomal microarray; CNVs: copy-number variations; CHD: congenital heart defects. karyotyping CHD cases (n = 362) CMA karyotyping CMA negative (n = 222) CNVs (n = 19) aneuploidy (n = 111) chromosomal structure abnormality (n = 10) induced labour (n = 10) induced labour (n = 19) induced labour (n = 31) induced labour (n = 60) 22q11.21deletion (n = 8) other microdeletion/duplication (n = 11) induced labour (n = 8) induced labour (n = 11) induced labour (n = 56) continue pregnancy (n = 166) Trisomy 13 (n = 19) Trisomy 21 (n = 31) Trisomy 18 (n = 61) PND continue pregnancy (n = 1) morbidity survivors (n = 11) intact survivors (n = 66) lost follow-up (n = 89) Table 3 – Genetic detection in different categories of fetuses with congenital heart disease (CHD) Classification of CHD Aneuploidy Abnormality of chromosome structure CNVs Other Single cardiac malformation (n = 181) 40 4 9 128 Multiple cardiac abnormalities (n = 181) 71 6 10 94 Isolated CHD (n = 220) 26 8 14 172 CHD with extracardiac anomaly (n = 142) 85 2 5 50 CNVs: copy-number variations. a reasonable outcome after surgery, as well as a good prognosis. In our study, ultrasonic results of some fetuses with CHD caused by aneuploidy only displayed mild cardiac malformations, although complex CHD combined with extra cardiac defects were more common in these cases. Besides, some symptoms such as mental disability cannot be found by prenatal ultrasound. In these cases, the results of genetic testing is of great importance, because this situation is easily ignored by patients and clinicians. However, several negative cases featured complex CHD and extra cardiac defects after karyotype and CMA testing, and these cases provide an important clue for the study of other factors that lead to CHD. Several limitations should be considered in the study when reviewing these findings. Firstly, a comprehensive analysis of all known CHD associated genes was not carried out. Secondly, the inheritance of CNVs in some cases with likely pathogenicity was not identified. Conclusion Karyotyping and CMA analysis was conducted in 362 CHD fetuses, and it was found that 38.7% of CHD fetuses had a positive genetic testing result. Aneuploidy is the major cause of CHD fetuses in our population. The combination of ultrasonic detection and genetic testing can effectively diagnose fetuses with cardiac malformations and extra cardiac defects, thus providing valuable information to the clinician and patients. Acknowledgements The authors would like to thank the families for their participation in this study. Author contributions Conception and design of the research: Fu C; Acquisition of data: Meng D, Hu X, Xie B; Analysis and interpretation of the 575