ABSTRACT
Objective To investigate the significances of karyotyping analysis on umbilical cord vein blood lymphocytes in the diagnosis of abnormal karyotypes in middle to late period of pregnant fetus.Methods A volume (0.5 ～ 1 ml) of umbilical cord vein blood was extracted from pregnant women in third trimester pregnancy with prenatal detection indications,and collected in sterilized anticoagulant tube.Lymphocytes were cultured and collected for karyotyping analysis after fixed and dropped on slides.Data were analyzed statistically.Results Lymphocytes were cultured successfully in 1 211 cases out of total 1 213 cases collected.Totally 142 abnormal karyotypes were found,which includes 81 cases (detection rate 6.68 ％) of non-heteromorphic abnormal chromosomes and 61 cases (detection rate 5.03％) of heteromorphic chromosomes.Among these abnormal karyotypes,50 cases (accounting for 35.21％ in total abnormal cases) of aneuploidy include 4 cases of chimerical karyotype.Structural abnormalities were found in 31 cases (accounting for 21.83％ in total abnormal cases) samples including 11 cases of translocations,17 cases of inversion and 3 cases of deletion.Conclusions Based on our findings,karyotyping analysis on umbilical cord vein blood lymphocytes could be an effective method for detect abnormal karyotypes in middle to late period of pregnant fetus and played an important role in prenatal diagnosis.
ABSTRACT
Objective To investigate the relationship between folate metabolism-related gene polymorphism and fetal congenital defects,and discuss the effect of genetic factors on fetal congenital defects.Methods Retrospective analysis was used to investigate the genotype and gene frequency of 5,1O-methylenetetrahydrofolate reductase (MTHFR) C677T,A1298C gene loci and ethionine synthase reductase (MTRR) A66G gene locus in 132 cases of adverse pregnancy pregnant women (case group) and 150 cases normal pregnant women (control group) at the same period.The statistical differences were analyzed between the levels of their serum folate,vitamin B12 (Vit B12) and homocysteine (HCY).Results In the serum of case group,folate was positively correlated with Vit B12,and was negatively correlated with HCY,only HCY of skeletal system defects(6 cases) was higher (t =3.409,P ＜ 0.05).Comparing genotypes frequency of the MTHFR C677T,A1298C gene loci and MTRR A66G gene locus in case group with control group,the difference above was not statistically significant (P ＞ 0.05).In these three gene loci C/T,A/C and A/G allele frequency with the control group,the difference above was not statistically significant (all P ＞ 0.05).Different genotype combinations of MTHFR C667T and A1298C gene loci in control groups had no statistically different from the control group (P ＞ 0.05),and there was no synergy.Conclusions Maternal folate metabolism-related MTHFR and MTRR genes polymorphisms can affect the metabolic products levels accordingly.However,the correlation between the changes and the genetic mechanism of fetal congenital defects needs more large samples study in depth.