Second trimester screening for trisomy 21 using ADAM12-S as a maternal serum marker / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the value of a disintegrin and metalloproteinase 12 secreting form (ADAM12-S) as a maternal serum marker in second trimester screening for trisomy 21 (Down syndrome, DS), and to develop an appropriate prenatal DS screening protocol.</p><p><b>METHODS</b>Serum samples were collected from 53 pregnant women carrying a trisomy 21 fetus and 621 pregnant women with matched gestational age and weight carrying a healthy fetus. ADAM12-S concentrations were determined with a time-resolved fluorescence immunoassay (TRFIA). Curve fitting by weighted regression and other statistical methods were conducted, and the model was optimized for prenatal trisomy 21 screening program in second trimester. ADAM12-S alone or in combination with other two- or three-combination test was selected as a serum marker for prenatal second-trimester screening of trisomy 21 by calculation of detection rate (DR) and false positive rate (FPR).</p><p><b>RESULTS</b>By comparison, the median multiple of the median (MoM) value of ADAM12-S in DS pregnancy group was higher than that of the control group (P< 0.01). When FPR = 5%, the DR of ADAM12-S was 28.3%, and the positive and negative likelihood ratios were 5.66 and 0.75, respectively. The DR of three-combination test of ADAM12-S, alpha-fetoprotein (AFP) and free beta subunit of human chorionic gonadotropin (β-HCG) has increased to 52.80% from 39.62% of the conventional two-combination test (AFP and free β-HCG). For women with a risk between 1/300 and 1/1000 by two-combination test for DS, the DR has increased from 39.62% to 47.12%, but FPR only increased by 0.8% after adding ADAM12-S as a maternal serum marker.</p><p><b>CONCLUSION</b>Considering the increased DR of pregnancies with a risk between 1/300 and 1/1000 in second trimester, ADAM12-S may provide a feasible maternal serum maker when combined with AFP and free β-HCG. The cost-effectiveness ratio is reasonable.</p>

Prenatal genetic study of fetuses with congenital heart diseases / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic abnormalities of fetuses with congenital heart diseases (CHD), and to provide guidance for the management of pregnancy and genetic counseling.</p><p><b>METHODS</b>Eighty-one fetuses with CHD detected by fetal echocardiography were analyzed by karyotyping after amniocentesis, cordocentesis or chorionic sampling. Then 22q11.2 deletion/duplication was detected by a competitive fluorescent multiplex short tandem repeat assay in 47 CHD fetuses without chromosomal abnormalities. With fluorescence in situ hybridization (FISH) using LSI dual color DNA probe, the deletion/duplication status was confirmed.</p><p><b>RESULTS</b>Thirty-four of 81 CHD fetuses had chromosomal anomalies, and 1 of the 47 CHD fetuses without chromosomal anomalies had duplication at chromosome 22q11. The incidence of aneuploidy associated CHD was 43.2%. The rate of chromosomal anomalies is higher in the cases associated with extra-cardiac anomalies than in that with isolated CHD (64.5% versus 28.0%). In the 35 fetuses with chromosomal abnormalities, 19 (54.3%) were trisomy 18.</p><p><b>CONCLUSION</b>Chromosomal abnormalities occurred in 43.2% of CHD cases and trisomy 18 is the most common aneuploidy. The likelihood of chromosomal anomaly increases when there is extracardiac involvement. Testing for the 22q11.2 microdeletion/duplication is recommended in all CHD fetuses without chromosomal anomalies. It is important for the further management of pregnancy and genetic counseling.</p>