RESULTS
A total of 40 fetuses at risk were recruited to undergo WES detection including 39 trio-WES, 1 proband+trio WES. The average gestational age was 19.5±4.8 weeks. 3 different types of samples were detected. And amniotic fluid, villi and induced fetal tissues accounted for 70%(28/40), 15%(15/40), 15%(15/40)of all cases, respectively. Five fetuses were found to have significant pathogenic variants, and likely pathogenic variants were detected in 3 fetuses. All diagnosed cases including four carriers of autosomal recessive(AR)variants were summarized in table 1. All of the unselected fetuses were divided into five groups (table 2), and we found that clinical diagnosis rate varies in different groups in 40 pregnancies. Fetuses with ultrasound anomalies showed higher diagnosis rate (6/10, 60%) relative to other groups. The families having a history of abnormal pregnancy or having a proband deceased with undiagnosed were diagnosed in 3 of 12 cases (25%). Then we focused on analyzing WES performance in different phenotypes with ultrasound anomalies, including malformation of the central nervous system (CNS), cardiovascular system, skeletal system, genitourinary system and craniofacial malformation and multiple malformations(table 3). We could see that the 2 fetuses with skeletal system malformation were all got to be diagnosed and detection rate reached 100%.while the cases having multiple malformations just got detection rate of 33%(1/3), and all 2 cases with genitourinary system abnormalities remained to be undiagnosed.