eight chromosomal abnormalities ( 29.7 % ) were detected , including 45 , x ( 2 cases ) , trisomy 21 ( 1 case ) , 46 , xy , -13 , +t ( 13,13 ) ( 1 case ) , 47 , xx , +18 ( 3 cases ) , 47 , xxy ( 1 case ) .
C0008625
chromosomal
C0013080
trisomy 21