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.