Prenatal diagnosis and genetic analysis of a fetus with partial deletion of Yq and mosaicism of 45,X / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal diagnosis and genetic analysis for a fetus with disorders of sex development (DSDs).@*METHODS@#A fetus with DSDs who was identified at the Shenzhen People's Hospital in September 2021 was selected as the study subject. Combined molecular genetic techniques including quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis (CMA), quantitative real-time PCR (qPCR), as well as cytogenetic techniques such as karyotyping analysis and fluorescence in situ hybridization (FISH) were applied. Ultrasonography was used to observe the phenotype of sex development.@*RESULTS@#Molecular genetic testing suggested that the fetus had mosaicism of Yq11.222qter deletion and X monosomy. Combined with the result of cytogenetic testing, its karyotype was determined as mos 45,X[34]/46,X,del(Y)(q11.222)[61]/47,X,del(Y)(q11.222),del(Y)(q11.222)[5]. Ultrasound examination suggested hypospadia, which was confirmed after elective abortion. Combined the results of genetic testing and phenotypic analysis, the fetus was ultimately diagnosed with DSDs.@*CONCLUSION@#This study has applied a variety of genetic techniques and ultrasonography to diagnose a fetus with DSDs with a complex karyotype.

Analysis for 6-methyladenine modification of DNA in chorionic tissue from aborted fetuses with monosomy 21 / 中华医学遗传学杂志

OBJECTIVE@#To study the correlation of genome-wide distribution of 6-methyladenine (6mA) of DNA in chorionic tissues from abortuses with monosomy 21.@*METHODS@#Genomic DNA was extracted from chorionic samples from four abortuses with monosomy 21 and four without. After quality and purity test, partial DNA was subjected to chromatin immunoprecipitation with anti-6mA antibody, and then identified by sequencing. The sequencing data was analyzed by using bioinformatic software for the difference in 6mA between the two groups.@*RESULTS@#Analysis of read peaks suggested that the control group have much more 6mA genes (n=4607) compared with the experiment group (n=1059). For chromosome 21, this difference is even more pronounced (8032 vs. 1769). Above results suggested that the level of 6mA modification in monosomy 21 is low. Gene ontology enrichment analysis and KEGG pathway enrichment analysis indicated that the absence of 6mA genes in monosomy 21 is closely related to the growth and development of embryo.@*CONCLUSION@#The 6mA modification of human genes may play a similar role to 5-methylcytosine (5mC) modification during the growth and development of embryos.

Karyotyping analysis on umbilical vein cord blood lymphocytes in middle-late pregnant fetus / 中国医师杂志

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.

Correlations between Fetal Congenital Cardiovascular Anomalies and Chromosomal karotypes / 中国医师进修杂志

Objective To investigate the distribution of congenital cardiovascular malformations in fetuses with chromosomal abnormalities.Method Congenital cardiovascular malformations of fetuses were diagnosed by prenatal ultrasonic cardiography from Jan 2011 to Sep 2013,and whose chromosomal karotype were tested by amniocentesis or cordocentesis.The association between chromosomal karyotypes and distribution of congenital cardiovascular malformations was analyzed.Result In 173 Fetuses with chromosomal abnormalities,20(11.56％) cases had congenital cardiovascular malformations,including seven 21-trisomies,eight 18-trisomies,three 13-trisomies and two 45,X.64％ (16/25) fetuses with congenital cardiovascular malformations accompanied with other malformations had chromosomal abnormalities.Only 1.87％ (52/4379) fetuses with normal karotype had congenital cardiovascular malformations.Conclusion Chromosomal abnormality is the most reason of complicate CHD.Chromosomal karotype test should be detected in fetus with complicate CHD.