Genetic analysis of the false positive trisomy 7 and false negative trisomy 18 by NIPT-PLUS / 中华医学遗传学杂志

OBJECTIVE@#To explore the cause of inconsistency between the results of trisomy 7 by expanded non-invasive prenatal testing (NIPT-PLUS) and trisomy 18 by prenatal diagnosis.@*METHODS@#A pregnant woman who received genetic counseling at Jiaozuo Maternal and Child Health Care Hospital on July 5, 2020 was selected as the study subject. NIPT-PLUS, systematic ultrasound and interventional prenatal testing were carried out. The middle segment and root of umbilical cord, center and edge of the maternal and fatal surface of the placenta were sampled for the validation by copy number variation sequencing (CNV-seq).@*RESULTS@#The result of NIPT-PLUS indicated that the fetus has trisomy 7. Systematic ultrasound has shown multiple malformations including atrioventricular septal defect, horseshoe kidney, and rocker-bottom feet. However, QF-PCR, chromosomal karyotyping analysis, and CNV-seq of amniotic fluid samples all showed that the fetus was trisomy 18. Validation using multiple placental samples confirmed that the middle segment of the umbilical cord contains trisomy 18, the center of the placenta contained trisomy 7, and other placental sites were mosaicism for trisomy 7 and trisomy 18. Notably, the ratio of trisomy 18 became lower further away from the umbilical cord.@*CONCLUSION@#The false positive results of trisomy 7 and false negative trisomy 18 by NIPT-PLUS was probably due to the existence of placental mosaicism. Strict prenatal diagnosis is required needed aneuploidy is detected by NIPT-PLUS to exclude the influence of placental mosaicisms.

Thromboelastogram parameters and MTHFR gene polymorphism in the diagnosis of adverse fetal pregnancy outcomes / 中国输血杂志

【Objective】 To retrospectively analyze the situation of patients with adverse fetal outcomes by thromboelastogram (TEG) parameters and, MTHFR gene polymorphism, so as to provide molecular biological diagnosis basis for patients with adverse pregnancy outcomes, and a new scheme for early prevention and treatment of women of childbearing age with MTHFR gene polymorphism. 【Methods】 A total of 100 women with adverse fetal pregnancy outcomes were selected as the adverse pregnancy group, and 100 healthy women of childbearing age with normal pregnancy history were selected as the controls. MTHFR gene C677T and A1298C polymorphisms were detected by polymerase chain reaction (PCR). TEG and blood coagulation were detected in the experimental group. 【Results】 The A1298C gene polymorphism(AA、CC、AC; A、C) was similar in both adverse pregnancy group and the controls. The frequency distribution of C, T allele of MTHFR gene C677T was statistically significant (χ2=4.60, P<0.05, OR =1.645, 95% CI: 1.042~2.595). TT and CT+ CC types showed significant different association with the factors of stillbirth(χ2 =7.49, P<0.05). MA value of TEG in the diagnosis of TT type of C677T genotypes MTHFR in 32 patients with adverse pregnancy outcome was analyzed. The area under the AUC curve of MA value was 0.795. 【Conclusion】 MTHFR C677T polymorphism TT with TEG parameter hypercoagulability is an important risk factor in the occurrence of pregnancy stillbirth in adverse pregnancy outcomes.

Correlation between irregular antibody profiles of non-Rh blood group system and incidence of hemolytic disease of the newborn, 53 cases / 中国输血杂志

【Objective】 To retrospectively analyze the irregular antibodies in 6 blood group systems other than the Rh blood group system in 53 pregnant women and analyze its correlation with the occurrence of hemolytic disease of the newborn(HDN). 【Methods】 19 473 pregnant women were screened for irregular antibodies by microgel detection technology combined with anti-human globulin (IgG+ C3d), and the positive samples screened out were further confirmed to understand the types and titers of irregular antibodies. Irregular antibody type determination experiment: IgG type irregular antibody titer was determined after mercaptoethanol (2-Me) inactivated the serum of the irregular antibody positive specimen, and then IgG and IgM type were determined by comparing the titer levels of irregular antibody. Three hemolysis tests and total bilirubin tests were performed on umbilical cord blood during delivery to analyze the level of jaundice and the occurrence of HDN. 【Results】 53 cases of irregular antibodies other than the Rh blood group system were detected in 19 473 pregnant women, with a positive rate of 0.27%, mainly MNS and Lewis blood group system.The incidence of HDN was 39.6% (21/53). There were 27 cases of IgM, 7 IgG, and 19 IgM + IgG. Comparison of total bilirubin detection between the low titer group (≤8) and the high titer group (>8) : the latter was significantly higher than the former (P<0.05); IgG antibody subtypes: IgG1 of the latter significantly increased (P<0.05), and so was IgG3 in former (P<0.05). There was a significant positive correlation between IgG1, IgG3 and total bilirubin. The area under the curve of IgG1+ IgG3 for HDN diagnosis, the sensitivity and specificity were 0.953, 0.900, and 0.967, respectively. 【Conclusion】 Other than Rh blood group system, irregular antibodies are mainly distributed in MNS and Lewis blood group system. The incidence of HDN is higher in Kell, Duffy and Kidd blood group systems after producing irregular antibodies. Non-antibody types are mostly IgM type or IgM + IgG mixed, and the incidence of HDN is not high; Patients with poor maternal history, either high or low titer, can be classified into IgG1 and IgG3 in early stages, and those with Abnormal results should be included into the perinatal management of high-risk women with regular checking.