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.

Genetic analysis of a family with 9q34.3 microdeletion and microduplication caused by abnormal chromosome balance structure / 中华医学遗传学杂志

OBJECTIVE@#To perform prenatal diagnosis, pedigree analysis, and genetic counseling of a pregnant woman who gave birth to a child with Kleefstra syndrome.@*METHODS@#Karyotype analysis, chromosomal microarray analysis (CMA), multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) were used of peripheral blood and amniotic fluid to find causes. Recurrence risk assessment was performed later.@*RESULTS@#The amniotic fluid sample showed a 9q34.3 microduplication of arr (hg19) 9q34.3 (140 168 806-141 020 389)× 3, which overlapped the 9q34.3 microdeletion region of proband. The pregnant woman was detected with a balanced translocation of ish, t(9;17)(9q34.3; qter) (9p+; 17p+,9q+, 17q+). No other abnormal results were found in the family.@*CONCLUSION@#Offspring who share the same chromosome segment deletion or duplication are always from parent who carries balanced chromosomal structural aberration.

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.

Chromosomal uniparental disomy 16 and fetal intrauterine growth restriction.

BACKGROUND: There is a well-documented association between prenatally diagnosed chromosomal uniparental disomy and poor pregnancy outcome. METHODS AND RESULT: In this study, we identified an intrauterine growth restricted fetus carrying a maternal UPD 16 with segmental hetero- and isodisomy using the Affymetrix CytoScan HD SNP-array and the UPDtool. We also performed FISH to exclude trisomy mosaicism of chr.16. We then explored the genetic mechanisms of how imprinted genes cause clinical abnormalities. Additionally, we reviewed the mUPD16 literature, compared the clinical phenotypes of our patient with other reported cases, and assessed the loss of autosomal-recessive genes in the regions of homozygosity. CONCLUSIONS: Considering UPD mechanism of potential impact on the function of the placenta, the genetic composition of chromosome 16, and the information previous literature reports, we have reason to believe that UPD16 correlates with IUGR.

Prenatal ultrasound application in diagnosis and treatment of twin reverse arterial perfusion syndrome / 中国医学影像技术

Objective To investigate the value of prenatal ultrasound in diagnosis and treatment of twin reverse arterial perfusion (TRAP) syndrome. Methods A retrospective study was performed in 5 TRAP cases, including ultrasound images, clinical data and pregnancy outcomes. The sonographic characteristics were summarized. Results Five TRAP cases were diagnosed during 13 to 28 weeks' gestation and confirmed after birth. Color Doppler unltrasonography revealed retrograde umbilical artery perfusion towards acardiac twin. Two of 5 cases ended up in induced abortion, 1 in spontaneous abortion, 1 was delivered at 37 weeks' gestation after ultrasound-guided feticide of the acardiac twin and 1 was monitored closely with ultrasound and delivered alive at 32~(+4) weeks' gestation. Conclusion Prenatal ultrasonography has great applicative value for TRAP syndrome in early diagnosis, choosing optimal treatment and prognosis assessment.