Prenatal diagnosis of a fetus with 8q13.3 microdeletion through chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) for the prenatal diagnosis of a fetus with structural anomaly detected by ultrasonography.@*METHODS@#The fetus and its parents were subjected to chromosomal karyotyping and CMA analysis.@*RESULTS@#The fetus was found to carry a 46,XN,t(8;11)(q21.2;q13) translocation which was inherited from its mother. CMA has found no copy number variations (CNVs) in both parents but a de novo 2.00 Mb microdeletion in the fetus at 8q13.3.@*CONCLUSION@#CMA is capable of detecting microdeletions and microduplications in fetuses with translocations detected by karyotyping analysis.

Genetic analysis and prenatal diagnosis for a Chinese pedigree affected with N-acetylglutamate synthase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with N-acetylglutamate synthase deficiency.@*METHODS@#Trio whole exome sequencing (WES) was carried out for the pedigree. Pathogenicity of the identified variant was predicted based on the latest recommendation of the American College of Medical Genetics and Genomics (ACMG). Prenatal diagnosis was provided for subsequent pregnancy through Sanger sequencing.@*RESULTS@#Trio WES showed that the proband has carried compound heterozygous c.68delG and c.796G>C variants of NAGS gene, for which the mother and father were respectively heterozygous carriers. Neither variant was reported previously. Based on the ACMG guidelines, the c.68delG variant was classified as "likely pathogenic" (PVS1+PM2), while the c.796G>C variant was classified as with "uncertain significance" (PM2+BP4). Sanger sequencing validated the above findings, and only detected the heterozygous c.796G>C variant in the amniotic fluid sample. The fetus was followed up till 6 month after birth with no obvious abnormality.@*CONCLUSION@#The compound heterozygous c.68delG and c.796G>C variants of the NAGS gene probably underlay the disorder in this pedigree, and the resulth asenabled genetic counseling and prenatal diagnosis for this pedigree.

Establishment of medians for maternal serum markers in Down's syndrome screening during the second trimester of pregnancy in north-central region of Jiangxi Province / 中南大学学报(医学版)

Objective:To establish the median databases of serum markers for Down's syndrome screening during the second trimester of pregnancy women in the north-central area of Jiangxi Province.Methods:Time-resolved fluorometry was used to detect the serum contents of AFP free β-hCG and uE3 in 57 548 pregnant women during 15-20 gestational weeks.Risk evaluation was conducted by LifeCycle 4.0.SAS 9.2 software was used to establish a model of the median fitted equation.The newly constructed median system was used to reassess the risk of Down's syndrome development in pregnant women.Results:The medianand built in medianof north-central region in Jiangxi Province are significantly different (Z=2.201,P=0.028).The relationship between the median of the triple index and the gestational age was analyzed by the weight regression model.The relationship between the MoM value and the weight was used to calculate the reciprocal model.The median of the new system was more efficiency than the built in median.In the median of the new system than the reference,the detection rate improved from 62.75％ to 72.55％,false positive rate reduced by 5.84％ to 4.94％.Conclusion:The newly constructed median system is suitable for Down's syndrome screening in the north-central region of Jiangxi Province.